Question

If 20% of something fused and 1420 grams did not fuse what is the total mass.

Answer 1

so, something fused, and that amount was 20% of the whole thing.

1420 grams did not fuse, and since a whole is 100%, 100% - 20% = 80%, so that has to be the remaining 80%.

since we know that 1420 is 80%, what is 20%?

$\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 1420&80\\ x&20 \end{array}\implies \cfrac{1420}{x}=\cfrac{80}{20}\implies \cfrac{1420}{x}=4\\\\\\ \cfrac{1420}{4}=x\implies 355=x \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \stackrel{\textit{total mass, \textit{na}mely 100\%}}{1420~~+~~355}\implies 1775$