Yacob wants to buy some chocolates for his friends. If he spends $5 on each
friend, he will have $20 left. If he spends $7 on each friend, he will have $4 left.
How much money does Yacob have?
If you take the remainder one way ($20.00) and subtract the remainder when done the other way ($4.00),
you get $20.00 - $4.00 = $16.00.
The amount spent per person differs by $2.00 ($7.00 - $5.00 = $2.00).
Divide the $16.00 by $2.00 and you get 8.
This means that there are 8 friends.
8 x $5.00 + $20.00 = $40.00 + $20.00 = $60.00
8 x $7.00 + $4.00 = $56.00 + $4.00 = $60.00.
Yacob has $60.00.