If x varies directly as​ y, and x equals=16 when y equals=4​, find x when y equals=10.

Question

If x varies directly as y, and x equals=16 when y equals=4, find x when y equals=10.

Answer 1

When we say x varies directly as y, we mean than x = c*y. If you are told what x and y are, you can solve for c.  After that, you can figure out what x is when y = 10.