Answer:
The present age of the mother is 30 years old
Step-by-step explanation:
Age of Jane = x
Age of Billy = 5x (Billy is five times as old as Jane)
Age of Sara = 15x (Their mother is now three times as old as Billy)
In 2 years Sara will be eight times as old as Jane, therefore:
15x + 2 = 8 (x + 2)
15x + 2 = 8x + 16
15x - 8x = 16 - 2
7x = 14
x = 14/7
x = 2 ⇒ 5x = 10x ⇒ 15x = 30
Jane's present age is 2, Billy's present age is 10 and Sara's present age is 30
The present age of the mother is 30 years old
