Chandler wants to buy a $500$ dollar mountain bike. For his birthday, his grandparents
send him $50$ dollars, his aunt sends him $35$ dollars and his cousin gives him $15$ dollars. He earns
$16$ dollars per week for his paper route. He will use all of his birthday money and all
of the money he earns from his paper route. In how many weeks will he be able
to buy the mountain bike?
$\mathrm{(A)}\ 24 \qquad\mathrm{(B)}\ 25 \qquad\mathrm{(C)}\ 26 \qquad\mathrm{(D)}\ 27 \qquad\mathrm{(E)}\ 28$
Let $x$ be the number of weeks.
Thus, we have the equation $50 + 35 + 15 + 16x = 500$.
Simplify,
$100 + 16x = 500$
$16x = 400$
$x = 25$
The answer is $\boxed{\textbf{(B)}\ 25}$