Question

Khan the barber shaved 40 % of his customers and gave a haircut to 80 % of his customers. He charged Rs. 7 for a shave and Rs. 5 for a haircut. If 20 % of customers who opted for a shave also had a hair-cut, what were Khan’s earnings if he had 75 customers (in Rs.)? *

Answer 1

Answer:

also find 20% for shave and haircut

Answer 2

Given,

Khan the barber shaved 40 % of his customers and gave a haircut to 80 % of his customers. He charged Rs. 7 for a shave and Rs. 5 for a haircut.

To find,

If 20 % of customers who opted for a shave also had a hair-cut, what were Khan’s earnings if he had 75 customers

Solution,

Total customers = 75

Let customers the barber shaved = A

Let customers who got haircut from barber = B

n(A) = 75 x 40/100 = 30

n(B) = 75 x 80/100 = 60

n(A∩B) = 75 x 20/100 = 15

n(A∪B) = n(A) + n(B) - n(A∩B) = 30 + 60 - 15 = 75

∴ Total income= (30 * 7) + (60 * 5) - (15 x 12) = 210 + 300 - 180 = Rs.330

Hence, Khan’s earnings if he had 75 customers was Rs.330.