Question

peter spent 40% of his money on books and 50% of his remaining money on toys. he had $21 left. how much money did peter have at first? (note: this may be really simple for some people, however mathematics for me is not a strong subject and i do need a lot of help, thanks.

Answer 1

40% of money on books
100-40=60
60% left

50% of remaining on toys
50% of 60%=30%
he has 21 left
21=30%

find 100%

$21=30%
divide by 3
$7=10%
times 10
$70=100%

he had $70 at first