VARIATIONS 3

x is inversely proportional to y. x=12 while y=5. Find y when x is 15.

Solution

x ⍺ k

      y

x = k

      y

12 = k

        5

k = 12 x 5

k = 60

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

k = 60, y= ?, x = 15.

x = k

      y

15 = 60

         y

y x 15 = 60  x  y   (multiply by y on both sides)

                y

15y = 60

15      15

Hence y = 4  .

TRY THIS…………….

x is inversely proportional to y. x=40 while y=4. Find y when x is 10.