The ratio of Liam's to Mark's money is 7:9. The ratio of Mark's to Ian's money is 8:1. If Liam has $112, how much less does Ian have than Mark?

Answer 1

Here is a neat way to do these
L : M = 7:9
M : I = 8 : 1

it would be nice to have L:M:I , so get M to be the same number
L:M = 7:9 = 56:72
M:I = 8:1 = 72:9

L:M:I = 56:72:9 = 56x : 72x: 9x

but I = 112
9x = 112
x = 112/9

so L = $696.89
M = 896.00
I = 112.00

state the conclusion