Answer:
<em>A. Tom is 15, and Tim is 6.</em>
Step-by-step explanation:
<em>Method A: Use the choices to find the answer</em>
Since you are given choices, you can try each choice until you see that one of the choices works.
Try choice A.
Ages now: 15 + 6 = 21 (This checks out.)
Ages in 3 years: Tom 15 + 3; Tim 6 + 3
(15 + 3)/(6 + 3) = 18/9 = 2 (This also checks out.)
The first choice works, so the answer is A.
<em>Method B: Write an equation to solve the problem</em>
Let Tom's age now = t.
Their ages add to 21, so Tim's age now is 21 - t.
In 3 years, Tom's age will be t + 3, and Tim's age will be 24 - t.
In 3 years, Tom's age will be twice Tim's age:
t + 3 = 2(24 - t)
t + 3 = 48 - 2t
3t = 45
t = 15
Tom's age is 15.
Tim's age is 21 - 15 = 6.
Tim's age is 6.
