Question

divide 80 into two parts so that the greater part is 4 times the smaller part.

Answer 1

Let the greater part be x and the smaller part be y..
therefore, x=4y (since greater part is four times the smaller part)
and x+y=80 (since the parts are of 80)
now solve the simultaneous eq.s
4y+y=80(since x=4y)
5y=80
y=16
therefore x=4*16
x=64

Answer 2

the ratio between the numbers would be x:4x since one number is 4 times the other, and the total is 80.
this means x+4x=80. solve using axioms:
x+4x=80
1x+4x=80
5x=80
5x/5=80/5
x=16

We have found that the cancellation is 10. therefore:
smallest number = 16 × 1 = 16
greatest number = 16 × 4 = 64

Ans=16,64