This is my first time so don't get mad if i am wrong.
We know there are 2 quarters in the envelope and dimes, nickles, and pennies. and gives us an unknown number ?/? now we need to find those numbers. lets say d=dimes, n=nickles, and p=pennies. number example: d-1, n-3, p-2 next add these numbers which is 5+2=7.