Question

what portions of 5/n=1.5/1.8

Answer 1

We can do cross multiplication:
$\frac{5}{n}$ = $\frac{1.5}{1.8}$
1.5n=5×1.8
n=$\frac{5*1.8}{1.5}$
n=6
check:
$\frac{5}{6}$ = $\frac{1.5}{1.8}$
both decimals are equivalent
0.8333...=0.8333...