Two quantities, x and y, are directly proportional. If x is halved, what happens to y?

A. It is doubled.

B. It is squared.

C. It is multiplied by 12.

D. It depends on the starting value of x.

C. It is multiplied by 1/2

Step-by-step explanation:

If x and y are directly proportional, that means that every change in x will result in same change in y. The change should be multiplicative/proportional, not additional. You can put it in this equation

y = kx

where k is a constant.

If the x is halved (x2 = 0.5x1), the y will change into

y2/y1 = kx2 / k1x1 = 0.5x1 / x1 = 0.5

The value of y will be half of its value before. In another word, it will be multiplied by 1/2