Question

If x varies inversely with y and x = 8 when y = 6, find y when x = 10.
(Points : 1)
a. y=5/12
b. y=4.8
c. y=7.5
d. y=40/3

Answer 1

Varying inversely is the opposite of varying directly... so you can solve direct proportions by dividing using:
x1/y1 = x2/y2, where x1, y1 are the first set of numbers and x2, y2 is the second set.
Likewise, you use multiplication if they vary inversely:
x1y1 = x2y2

In this case:
(8)(6) = (10)(y)
y = 8*6/10
y= 48/10
y= 4.8 @kittykat3

Answer 2

but if they had varied directly, you could have solved them like this:
8/6 = 10/y... and would solve it for "y"....