Hi LUANDATO,

There are a couple of ways to approach this question, but you'll likely find it easiest to just do the Algebra.

We're told that the AVERAGE number of products sold over 4 days is 13. This means that (4)(13) = 52 total products were sold.

The 4 sales totals are (X), (X+5), (X+3) and (X+12)... which gives us total of 4X + 20. We're asked to solve for the value of X.

4X + 20 = 52
4X = 32
X = 8

Final Answer: D

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

BTGmoderatorLU wrote:The numbers of products a store sold on 4 consecutive days were x, x + 5, x + 3 and x + 12. If the daily average of the products sold was 13, what is the value of x?

A.4
B.6
C.7
D.8
E.12

The OA is D.

Can any expert explain this PS question, please? Thanks.

We create the equation:

(x + x + 5 + x + 3 + x + 12)/4 = 13

4x + 20 = 52

4x = 32

x = 8

Answer: D

BTGmoderatorLU wrote:The numbers of products a store sold on 4 consecutive days were x, x + 5, x + 3 and x + 12. If the daily average of the products sold was 13, what is the value of x?

A.4
B.6
C.7
D.8
E.12

GIVEN: Average of the 4 values = 13
We can write: [x + (x+5) + (x+3) + (x + 12)/4 = 13
Multiply both sides by 4 to get: x + (x+5) + (x+3) + (x + 12) = 52
Simplify to get: 4x + 20 = 52
Subtract 20 from both sides: 4x = 32
Solve: x = 8
Answer: D

Cheers,
Brebt