Hi!
Let's write this as an equation.
t = Tim
s = Sue
j = Jim
2t = s
j = 15
t + s + j = 63
Put the value of j into the equation.
t + s + 15 = 63
Subtract 15 from both sides
t + s + 15 - 15 = 63 - 15
t + s = 48
Put the value of s into the equation.
t + 2t = 48
3t = 48
Divide by 3 on both sides
3t/3 = 48/3
t = 16
Put the value of t into the equation.
16 + s = 48
Subtract 16 from both sides
16 - 16 + s = 48 - 16
s = 32
Sue has 32 marbles.
Jim has 15.
Tim has 16.
We can check this by matching it with the given information.
Does Sue have 2 times as many marbles as Tim?
16 x 2 = 32
Yes!
Do Tim, Sue, and Jim's marbles add up to 63?
16 + 32 + 15 = 63
Yes!
So the answer is Tim has 16 marbles.
Hope this helps! :)
