Divide 72kg in a ratio of 1:3:5

Ratio  1:3:5
Sum  =  1 + 3 + 5 = 9 total parts.
Dividing 72 kg.

for 1:    = 1/9  * 72  = 8
for 3:    = 3/9  * 72  = 24
for 5:    = 5/9  * 72  = 40

So dividing 72kg into 1:3:5 =  8kg, 24kg, 72kg.