charles opened the trunk and found $6750 in $1 bills and $10 bills. If there were 150 more ones than tens, how many of each kind were there?

Question

anonymous · Answer

You need to set up a system of equations here. As you're looking for the number of each kind of bill, we'll make a variable for each kind: let $o$ be the number of ones, and $t$ be the number of tens. First, we know that together they make $$6750$. Second, we know how many more ones there are then tens:
$$
\begin{align}
o + 10t = 6750\
o + 150 = t\
\end{align}
$$
Now all you need to do is solve the system for $o$ and $t$.

anonymous · Answer

let the 10s be x while 1s be y
10x+y=6750              11x=6600
  +  x-y=150                  x=600,     y=450