If x varies directly as y, and x = 48 when y = 16, find x when y = 5.

X directly varies with y which means as x increases, y also increases. In this case, we represent a constant of proportionality of k.

Applying laws of proportionality,

x = k y

48 = k * 16

k = 3

when y is 5

x = k y

x = 3 * 5

x = 15