Tyrone has $60 and his sister has $135. Both get an allowance of $5 each week. Tyrone decides to save his entire allowance, but his sister spends all of hers each week plus an additional $10 each week. After how many weeks will they each have the same amount of money?
Tyrone starts with 60.
Sister starts with 135.
Each receives $5/week. Let w = weeks.
Tyrone will have
60 + $5*w after w weeks.
Sister will have 135 + $5*w - $5*w - $10*w.
Set them equal and solve for w. Post your work if you get stuck.