Question

Dave is three times older than Jim, and Jim is half Bill’s age. If their average age is 64, what is Jim’s age?

Answer 1

Dave is 96 years old.

Jim is 32 years old.

Bill is 64 years old.

d = 3j

j = 1/2b

64 = (d + j + b)/3

d = 3(1/2b)

d = 1.5b

64 = (1.5b + 1/2b + b)/3

Combine like terms.

64 = (3b)/3

Multiply both sides by 3.

192 = 3b

Divide both sides by 3.

64 = b

Because we have the value for b we can plug it into the other equations to solve for the other ages.

j = 1/2b

j = 1/2(64)

j = 32

d = 3j

d = 3(32)

d = 96