In a room, all except 18 of the people are over 50 years of age. 15 of the people in the room are under 50 years of age. If 10% of the people are at the age of 50 years, how many people are in the room>
A
27
B
30
C
33
D
36
Correct Answer: 30
let, Total number of people = x 50 years of age = x - 18 Under 15 years of age = 15 0.10x = x - x + 18 - 15 ∴x = 30 ans: 30