Answer:
x = 4
Step-by-step explanation:
If x varies directly with y
Directly Proportional:
[tex]y\proto x[/tex]
[tex]y=kx[/tex]
where, k is constant of proportionality
x = 2.5 when y = 10
[tex]10=k\cdot 2.5[/tex]
[tex]k=4[/tex]
Equation:
y=4x
Put y=16 and solve for x
[tex]16=4x[/tex]
[tex]x=4[/tex]
Hence, The value of x is 4 at y=16
