Question

HELP HELP HELP ASAP

Dad is 3 times as old as his son, Jim. In 20 years, Dad's age will be 2 years less than twice Jim's age. How old is Jim?

If D = dad's age now and J = Jim's age now, which of the following systems could be used to solve the problem?


D = 3J and D + 20 = 3J - 2
D = 3J and D + 20 = 2(3J + 20) - 2
D = 3J and D + 20 = 2(J + 20) - 2
D = 3J and D + 20 = 3J + 20 - 2

Answer 1

D = 3J and D + 20 = 2(J + 20) - 2

Explanation:

the first part is obvious. Dad is 3 times as old as his son = D=3J

the second part you're adding 20 years to both Dad and Jim = D + 20 and J+20. now Dad is 2 less than twice Jim's age -> D+20 = 2(J+20)-2