Question

one evening kaya devoted 2/5 of her study time to mathematics, 3/20 of her time to social science ,1/3 of her time to chemistry and the remaining 42 minutes to English. how much did she spend studying social science?

Answer 1

let the total time for studying be x
so according to the question
2x/5+3x/20+1x/3+42=x
53x/60+42=x
x=360
time spend for social science is 54 minutes