Question 147657
If y varies directly as x, then it fits a formula,
{{{y=kx}}}
From your examples,
{{{16=k(20)}}}
{{{k=16/20=4/5}}}
{{{y=(4x)/5}}}
When x=5, then
{{{y=(4x)/5}}}
{{{y=(4(5))/5}}}
{{{y=4}}}