Answer:
$105.
Explanation:
Using the givens:
Alvin's money and Sam's money, a = Alvin's, s = Sam's
a = s
We know that Alvin spent -35$ and Sam spent twice that number (2 x 35 = 70)
We know that the closest number that we can use to subtract a number which gives twice the remaining value of Alvin's, (2 x 35 = 70 + 35 (Alvin's spending's)), 105$.
105 - 35 = 70
105 - 70 = 35
35 is half 70 and 70 is twice 35.
There you have it, I hope it helps.