Gabrielle's age is three times Mikhail's age. The sum of their ages is 40. What is Mikhail's age?

__ years old

Gabrielle's age - 48

Step-by-step explanation:

Gabrielle's age is three times Mikhail's age.

G = 3M

The sum of their ages is 64.

G + M = 64:

Replace G with 3M

3M + M = 64

4M = 64

M = 16:

What is Gabrielle's age?

G = 3 (16)

G = 48