Expert: Abe Mantell - 6/6/2010

Question
The recipe for a loaf cake calls for 3/4 (fraction) pound of jelly beans in assorted colors. If 20 cakes are needed how many pounds of jelly beans will be used?

Jacqui has grades of 73 and 77 on her first two algebra tests. If she wants an average of at least 73, what possible scores can she make on her third test?

A. 69 or less
B. Greater than 69
C. Less than 69
D. 69 or greater

Answer
Hello Erin,

I gather the recipe is 3/4 of a pound of jelly beans PER CAKE...yes?
If so, then 20 cakes will require 20*(3/4) lbs = 15 lbs

Let x=the 3rd test score.  So, her average will be (73+77+x)/3, which she
wants to be atleast 73.  Thus, (73+77+x)/3 >= 73 (">=" is greater than or equal to)
multiplying by 3 gives 73+77+x>=219 ==> 150+x>=219 subtract 150 from both sides
==> x>=69
Answer D

Abe