AboutAbe Mantell Expertise Hello, I am a college professor of mathematics and regularly teach all levels from elementary mathematics through differential equations, and would be happy to assist anyone with such questions!
Experience Over 15 years teaching at the college level.
Organizations belong to NCTM, NYSMATYC, AMATYC, MAA, NYSUT, AFT.
Education/Credentials B.S. in Mathematics from Rensselaer Polytechnic Institute
M.S. (and A.B.D.) in Applied Mathematics from SUNY @ Stony Brook
Question I'm only 13 and i really suck at math, can you please go over my answers correct them, & explain why they're wrong?
1. The lease common multiple of 3, 4, 6, and 8 is
A. 8.
B. 24.
C. 72. -my answer
D. 96.
2. You're planning to buy a boat, a motor, and some miscellaneous boating equipment. The boat costs $325, the motor costs $225, and the equipment costs $79. If you've saved $438 toward these purchases, how much more do you need to save?
A. $181
B. $191 -my answer
C. $281
D. $291
3. Write 1,386 as the product of its prime factors.
A. 2 x 693
B. 2 x 3 x 231
C. 2 x 3 x 7 x 33 -my answer
D. 2 x 3 x 3 x 7 x 11
4. 45 - 15 - 15 =
A. 0.
B. 1.
C. 15. -my answer
D. 30.
5. At a local store you find the following prices listed:
Cellophane tape 2 rolls for $1.28
Note pads 3 pads for .87
Highlighters 1 for 1.59
Ink cartridges 2 boxes for 1.98
How much would you pay for one roll of tape, two note pads, two highlighters, and two boxes of ink cartridges?
A. $4.50
B. $5.72
C. $6.38 -my answer
D. $8.07
6. At the beginning of the week the balance in your checkbook was $298.72. During the week you made a deposit of $425.69. You also wrote checks for $29.72, $135.47, and $208.28. At the end of the week you received a letter from the bank indicating that they had deducted a $5.00 service charge from your account. How much is in your account at the end of the week?
A. $47.22 -my answer
B. $52.22
C. $345.94
D. $350.94
7. Find the product of 987.2365 and 1,000.
A. 9,872,365
B. 987,236.5
C. .9872365 -my answer
D. .09872365
8. A used car is priced at $2,695. If you borrow the money for the car, your payments will be $122 a month for 30 months. How much will you save by paying cash?
A. $233 -my answer
B. $333
C. $965
D. $1,075
9. Subtract the quotient of 18 and 2 from the sum of 22 and 9.
A. 4
B. 5
C. 22
D. 23 -my answer
Questions 10-11: These questions are based on this circle graph, which shows how an electrical contracting company divides its monthly income.
10. In the circle graph above, you can see that 47% of the company's monthly income is used to pay the owner's personal salary. If the amount of the owner's personal salary was $2,176.10 this month, what was the company's total monthly income this month?
A. $4,630
B. $8,704 -my answer
C. $10,227
D. $21,590
11. What percent of the contractor's income is spent on salaries?
A. 25%
B. 47%
C. 72% -my answer
D. 76%
12. Over a four-week period, Gail earned the following commissions?
Week 1 $250.00
Week 2 310.00
Week 3 275.00
Week 4 195.00
What was her average weekly commission for the period?
A. $205.00
B. $207.50
C. $240.00.
D. $257.50
13. A strip of wood 66 inches long is to be cut into 51/2-inch pieces. How many pieces can be cut?
A. 12 -my answer
B. 14
C. 30
D. 33
14. The dimensions of a property are shown in the figure below.
How much would it cost to fence in this property if fencing costs $5.00 per foot?
A. $385
B. $825
C. $1,425
D. $1,925
15. A student answered three questions on a 40-question test incorrectly. What percent did the student answer correctly?
A. 7.5%
B. 37%-my answer
C. 43%
D. 92.5%
16. The telephone rates between your city and the city where your brother lives are $.54 for the first minute and $.22 for each additional minute. Calculate the cost of a 10-minute call to your brother.
A. $2.20
B. $2.52
C. $5.08
D. $5.40-my answer
17. A piece of pipe is 303/4 inches long. If five pieces, each 41/3 inches long, are cut from the pipe, how many inches of pipe remain?
A. 9 1/12 inches
B. 9 3/4 inches -my answer
C. 26 5/12 inches
D. 26 3/4 inches
18. Find the difference between the product of 26.22 and 3.09 and the sum of 3.507, 2.08, 11.5, and 16.712.
A. 4.489
B. 6.511
C. 47.2208
D. 58.3108
19. If 31/2 pounds of bananas cost $.98, how much would one pound cost?
A. $.14
B. $.18
C. $.20-my answer
D. $.28
20. A real estate broker sold your house for $72,000. The broker's commission was 6% of the selling price. How much would you get for the house after the commission is paid?
A. $67,680
B. $70,800-my answer
C. $73,200
D. $76,320
Answer Hello Amber,
Wow, you have many questions! Usually I would not answer so many at once, but I'll make an exception this time. :-)
1. The least common multiple of 3, 4, 6, and 8 is
A. 8.
B. 24.
C. 72. -my answer
D. 96.
The least common multiple is the SMALLEST number that can be divided
by each of the numbers with no remainder. Notice that 24 is a multiple
of them all, and is the smallest one.
2. You're planning to buy a boat, a motor, and some miscellaneous boating equipment. The boat costs $325, the motor costs $225, and the equipment costs $79. If you've saved $438 toward these purchases, how much more do you need to save?
A. $181
B. $191 -my answer
C. $281
D. $291
Need: $325 + $225 + $79 = $629
Have: $438
Difference: $629-$438 = $191, your answer is correct.
3. Write 1,386 as the product of its prime factors.
A. 2 x 693
B. 2 x 3 x 231
C. 2 x 3 x 7 x 33 -my answer
D. 2 x 3 x 3 x 7 x 11
Your answer is not correct since 33 is not prime, 33=3x11
So, answer D.
4. 45 - 15 - 15 =
A. 0.
B. 1.
C. 15. -my answer
D. 30.
Your answer is correct.
5. At a local store you find the following prices listed:
Cellophane tape 2 rolls for $1.28
Note pads 3 pads for .87
Highlighters 1 for 1.59
Ink cartridges 2 boxes for 1.98
How much would you pay for one roll of tape, two note pads, two highlighters, and two boxes of ink cartridges?
A. $4.50
B. $5.72
C. $6.38 -my answer
D. $8.07
Your answer is correct.
6. At the beginning of the week the balance in your checkbook was $298.72. During the week you made a deposit of $425.69. You also wrote checks for $29.72, $135.47, and $208.28. At the end of the week you received a letter from the bank indicating that they had deducted a $5.00 service charge from your account. How much is in your account at the end of the week?
A. $47.22 -my answer
B. $52.22
C. $345.94
D. $350.94
Add deposits and subtract the check amounts and fee(s):
$298.72 + $425.69 - $29.72 - $135.47 - $208.28 - $5.00 = $345.94
Answer "C"
7. Find the product of 987.2365 and 1,000.
A. 9,872,365
B. 987,236.5
C. .9872365 -my answer
D. .09872365
Product means "multiplication" so 987.2365 x 1000 gives choice "B"
8. A used car is priced at $2,695. If you borrow the money for the car, your payments will be $122 a month for 30 months. How much will you save by paying cash?
A. $233 -my answer
B. $333
C. $965
D. $1,075
Payments = $122 x 30 = $3660
Saved by paying cash: $3660 - $2695 = $965, answer "C"
9. Subtract the quotient of 18 and 2 from the sum of 22 and 9.
A. 4
B. 5
C. 22
D. 23 -my answer
(22 + 9) - 18/2 = 31 - 9 = 22, answer "C"
Questions 10-11: These questions are based on this circle graph, which shows how an electrical contracting company divides its monthly income.
10. In the circle graph above, you can see that 47% of the company's monthly income is used to pay the owner's personal salary. If the amount of the owner's personal salary was $2,176.10 this month, what was the company's total monthly income this month?
A. $4,630
B. $8,704 -my answer
C. $10,227
D. $21,590
47% of x is $2176.10 ==> 0.47x=2176.10 ==> x=2176.10/0.47
So x=4630 ... answer "A"
11. What percent of the contractor's income is spent on salaries?
A. 25%
B. 47%
C. 72% -my answer
D. 76%
I'd need to see the graph.
12. Over a four-week period, Gail earned the following commissions?
Week 1 $250.00
Week 2 310.00
Week 3 275.00
Week 4 195.00
What was her average weekly commission for the period?
A. $205.00
B. $207.50
C. $240.00.
D. $257.50
(250 + 310 + 275 + 195)/4 = 257.50, answer "D"
13. A strip of wood 66 inches long is to be cut into 51/2-inch pieces. How many pieces can be cut?
A. 12 -my answer
B. 14
C. 30
D. 33
66/5.5, since 5 1/2 = 5.5, Your answer is correct.
14. The dimensions of a property are shown in the figure below.
How much would it cost to fence in this property if fencing costs $5.00 per foot?
A. $385
B. $825
C. $1,425
D. $1,925
I'd need to see the diagram.
15. A student answered three questions on a 40-question test incorrectly. What percent did the student answer correctly?
A. 7.5%
B. 37%-my answer
C. 43%
D. 92.5%
37 correct out of 40 ==> 37/40 = 0.925 = 92.5%, answer "D"
16. The telephone rates between your city and the city where your brother lives are $.54 for the first minute and $.22 for each additional minute. Calculate the cost of a 10-minute call to your brother.
A. $2.20
B. $2.52
C. $5.08
D. $5.40-my answer
A 10 minute call: first minute cost $0.54, the next 9 minutes cost
$0.22 per minute...so the next 9 minutes cost $0.22 x 9 = $1.98
Total cost = $0.54 + $1.98 = $2.52 Answer "B"
17. A piece of pipe is 30 3/4 inches long. If five pieces, each 4 1/3 inches long, are cut from the pipe, how many inches of pipe remain?
A. 9 1/12 inches
B. 9 3/4 inches -my answer
C. 26 5/12 inches
D. 26 3/4 inches
5 x 4 1/3 = 20 5/3 = 21 2/3, so 30 3/4 - 21 2/3 = 9 1/12
Answer "A"
18. Find the difference between the product of 26.22 and 3.09 and the sum of 3.507, 2.08, 11.5, and 16.712.
A. 4.489
B. 6.511
C. 47.2208
D. 58.3108
19. If 3 1/2 pounds of bananas cost $.98, how much would one pound cost?
A. $.14
B. $.18
C. $.20-my answer
D. $.28
$0.98 / 3.5 = $0.28 per pound, answer "D"
20. A real estate broker sold your house for $72,000. The broker's commission was 6% of the selling price. How much would you get for the house after the commission is paid?
A. $67,680
B. $70,800-my answer
C. $73,200
D. $76,320
6% of $72000 = 0.06 x $72000 = $4320
You would get $72,000 - $4320 = $67,680 Answer "A"
