Question

Bob's age is 4 times greater than Susanne's age. Dakota is three years younger than Susanne. The sum of Bob's, Susanne's, and Dakota's ages is 93. What is Susanne's age?

Answer 1

Susanne is 16 years old.

b = Bob's age

s = Susanne's age

d = Dakota's age

Bob's age is 4 times greater than Susanne's age:

b = 4s

Dakota is three years younger than Susanne:

d = s - 3

The sum of Bob's, Susanne's, and Dakota's ages is 93:

b + s + d = 93

 solve these equations:

b = 4s

d = s - 3

b + s + d = 93

and get:

b = 64 years

s = 16 years

(remember that s = Susanne) 

d = 13 years