anceer wrote:

In Net's hair salon 42% of the customers dye their hair blond, 36% dye their eyebrows blond and 35% straighten their hair. 20% of the customers have none of these three procedures, while 12% take all of these three procedures. What percent of the customers come for exactly 2 of these 3 procedures?

A 5%

B 9%

C 12%

D 15%

E 21%

The answer is B

Let a total of 100 people visit the salon.

Total = 100

Dye hair blonde (A) = 42 % = 42

Dye Eyebrows blonde (B) = 36% = 36

Straighten Hair (C) = 35% = 35

Neither = 20% = 20

All Three = 12% =12

Total = A+B+C - (Sum of Exactly Two group overlaps) - 2*(All three) + Neither

100 = 42+36+35 - (Sum of Exactly Two group overlaps) - 2*12 + 20

(Sum of Exactly Two group overlaps) = 9

%of customers coming for exactly 2 of the 3 procedures = 9%