Dad is 4 times as old as his son jim. in 10 years, dad's age will be 20 years more than twice jim's age. how old is jim?
10 years old
15 years old
30 years old

Jim is 15 years old

Jim = 15 years old, 
Dad is 4 times as old as his son Jim = = 15 x 4 = 60

In 10 years, Jim = 15 + 10 =25 years old
Dad = 60 + 10 = 70

Dad's age will be 20 years more than twice Jim's age

Dad's age = 20 + 2(25) = 70

The correct answer is 15 years old. If Jim is currently 15 years old, then his dad is 60 years old. That means that in 10 years, Jim will be 25 and Dad will be 70. Seventy is equal to 25 times 2 plus 20.