Answer
See below
Work Step by Step
Chemicals A and B combine in the ratio 3:5 in producing the chemical C.
Initial amount of A: 15g
Amount of C: 30g
For chemical A: $\frac{3}{8}C$
For chemical B: $\frac{5}{8}C$
Since we know chemicals A and B combine in producing the chemical C, obtain:
$\frac{3}{8}(30)+\frac{5}{8}(30)=30
\\11.25+18.75=30$
Hence, the minimum amount of B required to produce 30 g of C is $18.75$g
