Question

If y varies directly as x, and y=5/2 when x=15, find y when x =3

Answer 1

To find the value of y when x=3, we first determine the constant of variation k from the given values (x=15, y=5/2), then apply it to calculate y. The constant k is found to be 1/6, and thus y equals 1/2 when x=3.

Step-by-step explanation:

If y varies directly as x, it means there is a constant k such that y = kx. When x=15, we are told that y=5/2. From this, we can find the constant of variation k:

y = kx
5/2 = k(15)
k = (5/2) / 15
k = 1/6

Once k is found, we can use it to find y when x = 3:

y = (1/6)(3)
y = 1/2

Therefore, when x = 3, y is equal to 1/2.