The table above shows the average (arithmetic mean) price

Hi All,

We're told that the table above shows the average (arithmetic mean) price per dozen eggs sold in a certain store during three successive months - and that 2/3 as many dozen were sold in April as in May, and twice as many were sold in June as in April. We're asked for the average price per dozen of the eggs sold over the three-month period. This question can be solved by TESTing VALUES and doing the necessary Arithmetic. It's also worth noting that since the answers are relatively 'close' together, we will have to be precise with our calculations.

IF....
2 dozen eggs were sold in April
3 dozen eggs were sold in May
4 dozen eggs were sold in June

Total price = (2)($1.26) + (3)($1.20) + (4)($1.08) = $2.52 + $3.60 + $4.32 = $10.44
Average price per dozen = $10.44/9 = $1.16

Final Answer: D

GMAT assassins aren't born, they're made,
Rich

BTGmoderatorDC wrote:


The table above shows the average (arithmetic mean) price per dozen eggs sold in a certain store during three successive months. If 2/3 as many dozen were sold in April as in May, and twice as many were sold in June as in April, what was the average price per dozen of the eggs sold over the three-month period?

A. $1.08
B. $1.10
C. $1.14
D. $1.16
E. $1.18


OA D

Source: Official Guide

Solution:

We can create the equations:

A = 2M/3

3A = 2M

3A/2 = M

1.5A = M

and

J = 2A

Therefore, the average price per dozen eggs sold over the three-month period is:

(A x 1.26 + 1.5A x 1.20 + 2A x 1.08)/(A + 1.5A + 2A)

(1.26A+ 1.8A + 2.16A)/(4.5A)

5.22A/(4.5A) = 5.22/4.5 = 1.16

Alternate solution:

We can let the number of dozens of eggs sold in May be 6; thus, the number of dozens of eggs sold in April is 2/3 x 6 = 4, and the number of dozens of eggs sold in June is 2 x 4 = 8.

Therefore, the average price per dozen eggs sold over the three-month period is:

(4 x 1.26 + 6 x 1.20 + 8 x 1.08)/(4 + 6 + 8)

20.88/18 = 1.16

Answer: D