Henry earns 1300 and spends 30% of the money
= 30% X 1300
= 30/100 X 1300
= 30 X 13 = 390
so, he spends 39 on rent.
he spends 12% of 1300
= 12/100 X 1300
= 12 X 13
= 156
so he spends 156 on bill.
now he spends total (156 + 390 ) = 546 on rent and bill.
so he was left with = (1300 - 546) = 754
here is another method
he spends total (30% + 12%) = 42% on rent and bill.
that means he spends on bill and rent = 42% of 1300
= 42/100 X 1300
= 42 X 13
=546
hence, he is left with = (1300 - 546) = 754