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?

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