Alex spent 1/3 of his pocket money on a toy airplane and 2/3 of the remainder on a toy robot. he had $20 left. how much did he spend altogether?

Answer with explanation:

Let Pocket  money Alex =$ x

Amount of money spent on toy Airplane

Money left with Alex

Amount of money spent on toy Robot

Amount left after these two expenses=$ 20

Writing the above statement in equation form

So, Money spent by Alex =$90-$20

                      =$ 70