| Subject | Date Asked | Expert |
|
| Problems involving two variables | 7/5/2009 | Abe Mantell |
Q: I am having a very hard time understanding how to do this problem and I was wondering if you could ...
A: Let x=# of burgers you need to buy, and y=# of hot dogs you need to buy Thus, 1. x+y=23 (since there ...
|
| quadratic word problem | 6/11/2009 | Abe Mantell |
Q: I'm trying to help some students with quadratic application probs. The one that I'm not sure how to ...
A: Assuming the bucket is at ground level, with y=0, we just need to determine the x-value of where it ...
|
| Can Help me solve this question | 6/9/2009 | Abe Mantell |
Q: (Quadratic Equation) 1)Solve these equation.(use 2^x=y) 2^2x-9(2^x)+20=0 2)if p and q are the root ...
A: Wow, you sure have many questions! How about I do a couple and see if you can do the others? 1. Do ...
|
| Quadratic Function | 6/8/2009 | Abe Mantell |
Q: Find two numbers whose sum is 30,such that the sum of their squares is a maximum.
A: Let x=one of the numbers, then 30-x is the other. The sum of the squares will then be: x^2 + ...
|
| Quadratic Equation | 6/7/2009 | Abe Mantell |
Q: A strip of wire of length 28cm is cut into two pieces.One piece is bent to form a square of side x ...
A: If the square has sides of length x, then the total perimeter is 4x. Thus, 28-4x is left over for ...
|
| college algebra | 6/6/2009 | Abe Mantell |
Q: Flying with the wind, a small plane can fly 600 mi in 3 h. Against the wind, the plane can fly the ...
A: Let x=the rate of the plane in calm air, and y=the rate of the wind So, using distance=rate*time we ...
|
| Need help with problem setup | 6/4/2009 | Abe Mantell |
Q: I am helping a friend with her math for an upcoming test for adult education. It has been years ...
A: 20% of the 25 ounce solution is pure alcohol, thus only 5 ounces are pure alcohol (i.e. 20% of 25 ...
|
| Death to Quadratics... | 6/4/2009 | Chanda Walker |
Q: Okay, thank you for looking. I am having serious problems with my grade 10 math. If you could go ...
A: Whoa! No killing quadratics. That is an insult to a mathematician! To find a maximum of a ...
|
| Math | 6/3/2009 | Abe Mantell |
Q: I have a question. If the question says that they give you a surface area and radius, and your ...
A: I need to know what is the shape of the object? Is it a sphere? A cylinder? As for the vase, I ...
|
| High school word problem involving inequalities | 4/29/2009 | Chanda Walker |
Q: this is myThe age of the youngest of three sisters is 7 years less than twice the age of the middle ...
A: I showed you how to solve using inequalities. Here is the work. x + (x + 7)/2 + 2x + 11 >20 7/2 x ...
|
| High school word problem involving inequalities | 4/26/2009 | Chanda Walker |
Q: this is myThe age of the youngest of three sisters is 7 years less than twice the age of the middle ...
A: youngest = x x = 2(middle) - 7 2x + 11 = oldest Solve for the age of the middle in terms of x . . ...
|
| Car word problem | 4/24/2009 | Chanda Walker |
Q: Two cars are driving around a two-mile track. One car makes a lap every eighty seconds. The other ...
A: You need to covert from seconds to speed. speed = distance/time speed1 = 1/80 laps/second speed2 = ...
|
| word prblem grade two | 4/23/2009 | Chanda Walker |
Q: i am a 3 digit number with 3 different digits.all my digits are written with straight lines only. my ...
A: Well, let's list the numbers that have only straight lines. 1 4 7 There are only 3 of them as I ...
|
| Word Problem | 4/21/2009 | Chanda Walker |
Q: Zach arrives from Phoenix to somewhere at 60mph. Zach drives back from somewhere to Phoenix at ...
A: No not quite . . . Let x = the distance traveled between Phoenix and somewhere. He took x/60 hours ...
|
| Quadratic Word Problem | 4/21/2009 | Chanda Walker |
Q: I asked everybody these two questions and spent the whole day trying to figure it out. Even my ...
A: If you can find the vertex, then you know the maximum height. Vertex: (t, hmax) where t is the ...
|
| Easy story problem... | 4/4/2009 | Chanda Walker |
Q: I have a relatively simple story problem, but my math skills are terrible. I'm trying to figure ...
A: A lightyear is much more than you have approximated. It is more like 6 trillion miles. So the ...
|
| Math word problem | 4/2/2009 | Chanda Walker |
Q: I am trying to help my 6th grader with word problems. I am too old to remember this stuff; would ...
A: I'm happy to help. Let's create some variables. p = number of pencils e = number of erasers p + e ...
|
| Elementary Word Problem | 3/30/2009 | Chanda Walker |
Q: What common fraction is one third of the way from 1/4 to 1/3? I know that you subtract 1/3 from 1/4 ...
A: difference is 1/3 - 1/4 = 4/12 - 3/12 = 1/12 One third of 1/12 = 1/36 1/4 + 1/36 = 9/36 + 1/36 = ...
|
| word problem | 3/30/2009 | Chanda Walker |
Q: An heiress is throwing a party on her yacht. She is in her room till 12 o'clock. at twelve thirty ...
A: All we know is "the current which is going in the direction of the boat after it turns around." ...
|
| lottery probabilties | 3/29/2009 | Chanda Walker |
Q: There is a lottery where there are 5 numbers drawn out of 45. You have the option of picking 7, 9, ...
A: 40C4 is said: 40 choose 4 This is standard notation for permutation and combinations. nCk (n ...
|
| lottery probabilties | 3/28/2009 | Chanda Walker |
Q: There is a lottery where there are 5 numbers drawn out of 45. You have the option of picking 7, 9, ...
A: The way I think about this is that there are 5 red balls and 40 blue balls in a bag. The red balls ...
|
| CONFUSED NEED HELP | 3/28/2009 | Chanda Walker |
Q: Students walking to class cut the corner across the parking lot. Going the long way meant walking ...
A: You need to use the Pythagorean theorem. It says that if you have a right triangle, you can ...
|
| Elementary Math Word Problem | 3/26/2009 | Chanda Walker |
Q: A bag contains five red marbles, three green marbles, and four blue marbles. How many green marbles ...
A: Probability of draw a marble of "whatever" color is: # of marble's that have that color divided by ...
|
| word prob | 3/25/2009 | Chanda Walker |
Q: please help! im so confused A single-engine plane started out in high tail winds and made a trip of ...
A: (v+w) = 500/2 = 250 km/h ********* I'll assume the wind hasn't abated on the return trip though it ...
|
| Find the Surface area of a Box | 3/24/2009 | Chanda Walker |
Q: Find the surface area of a box that measures 30 centimeters by 30 centimeters by 25 centimeters. ...
A: h = 30 w = 30 d = 25 The area of the top and bottom (each) are: w*d = 30*25=750 The area of the ...
|
| word problem | 3/23/2009 | Chanda Walker |
Q: Jane has a bag containing a mix of seeds for purple flowers, yellow flowers and orange flowers in ...
A: sorry! My little one got a skinned knee in the middle of working this problem and I totally lost my ...
|
| Using a Quadratic Function in an Application | 3/21/2009 | Chanda Walker |
Q: If an object is propelled upward from ground level with an initial velocity of 48.6 feet per second, ...
A: h = -16t^2 + 48.6 t We need to solve this such that h=0. 0 = -16t^2 + 48.6 t 0 = t(-16t + 48.6) t ...
|
| Distnce, time, rate | 3/20/2009 | Chanda Walker |
Q: I can't understand how to set up this problem. What am I missing in setting it up. A six-passenger ...
A: Yikes! That is a lot of wind! That is the speed of the airplane not the wind I think. 5v + 5ws = ...
|
| word problem | 3/19/2009 | Chanda Walker |
Q: March is the month when the National Collegiate Basketball champion is determined. Currently there ...
A: March is the month when the National Collegiate Basketball champion is determined. Currently there ...
|
| math word problem | 3/18/2009 | Chanda Walker |
Q: There are 1200 students at Kings Middle school. Each student at Kings take 6 classes a day. Each ...
A: 1200 students 6 classes per day 30 in the class 1 teacher 5 classes per teacher per day 1200 ...
|
| Trigonometry word problem | 3/18/2009 | Chanda Walker |
Q: A vertical telegraph pole standing alongside an inclined highway casts a 52 foot shadow down the ...
A: Let's form a triangle whose sides are the pole, the hill, and the edge of the shadow. It says that ...
|
| two equations with two variables | 3/17/2009 | Chanda Walker |
Q: the sum of two numbers is 18 less than twice the first number. their difference is 32 less than ...
A: x + y = 2x - 18 x - y = y - 32 y = x - 18 x = 2y - 32 x = 2*(x - 18) - 32 x = 2x - 36 - 32 68 = x ...
|
| math word problem | 3/16/2009 | Chanda Walker |
Q: Rachel ran an average of 30 miles this week. She ran 8 miles on Monday. How many miles did she run ...
A: This problem is worded funny. If the question is: Rachel ran an average of 30 miles PER DAY this ...
|
| LPP | 3/15/2009 | Chanda Walker |
Q: A local herb shop is producing two natural perfumes: Gentle Rose and Rich Gardenia. The owner, who ...
A: P = GR * $4 + RG * $5 C = GR * $3 + RG * $6 <= $9000 V = GR*2 + RG*1.5 <= 3000 Solving the ...
|
| logic problem | 3/15/2009 | Chanda Walker |
Q: In a certain mythical community,a stranger meets three other natives and asks them, "How many of you ...
A: Sorry about the delay--my wifi went wonky. So I think we have to make these assertions: 1) All ...
|
| Logic problem | 3/15/2009 | Chanda Walker |
Q: Alice, Betty, Carol and Dorothy were lifeguard, a lawyer, a pilot or a professor. Each wore a white, ...
A: Where are you getting these problems from? They are great fun. I'd like to have a whole slew of ...
|
| Logic problem | 3/15/2009 | Chanda Walker |
Q: Alice, Betty, Carol and Dorothy were lifeguard, a lawyer, a pilot or a professor. Each wore a white, ...
A: Here is what we know: A (not a professor) (not blue) (due to mutual envy) B (not a lifeguard) ...
|
| compound interest | 3/14/2009 | Chanda Walker |
Q: a sum of money is invested at a half yearly compound interest rate of 5%. if the difference of ...
A: FV = P(1 + r/n)^t*n P unknown r = 0.05 n = 1 t = 1 (Since the interest rate is given in half ...
|
| compound interest | 3/12/2009 | Chanda Walker |
Q: a man borrows $12000 at a certain rate of compound interest per annum.his loan becomes 12730.80 at ...
A: I assume it compounds yearly. 12730.80 = 12000*(1 + r)*(1 + r) 12730.80 = 12000*(1 + r)^2 1.0609 = ...
|
| Word problem help | 3/10/2009 | Chanda Walker |
Q: I found these online and answered them wrong. Please help me solve them. Note: They are not homework ...
A: It's ok even if they are homework from school but I like to have people try to the problems before I ...
|
