Question

the ratio of the zinc and copper in an alloy is 7 is to 9 If the weight of the copper in an alloy is 11.7 kg find the weight of the zinc in it

Answer 1

let the weight of the zinc is7x & 9x
the weight of the copper=11.7
A/Q
9x=11.7
x=1.3
the weight of the zinc is7x=7×1.3=9.1

Answer 2

let the weight = X
7/9=X/11.7
7/9×11.7=X
the answer is = 9.1
weight of the zinc =9.1