Question

If m + 4n = 2n + 8m ; what is the ratio of n to m ?

a) 1:4, b) 1:-4, c) -4:1, d) 2:7, e) 7:2

Answer 1

`m + 4n = 2n + 8m\\ 7m=2n\\ m=(2)/(7)n\\\\ (n)/(m)=(n)/((2)/(7)n)=(7)/(2)`

Answer 2

m + 4n = 2n + 8m

To answer the ratio, massage this equation around to find ' n/m ' .

Let's subtract 'm' from each side:

4n = 2n + 7m

Subtract '2n' from each side:

2n = 7m

Divide each side by 'm' :
2 (n/m) = 7

Divide each side by 2 :

n/m = 7/2 . . . . . there's your ratio. That's choice-'e'.