VARIATIONS 2

x is directly proportional to y. x=12 while y=4. Find y when x is 60.

Solution

x ⍺ y

x = ky

12 = k x 4

12 = 4k

4      4

k = 3

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

k = 3, y= ? x = 60.

60 = 3   x   y

60 = 3y          [dividing by 3 both sides]

3      3

y = 20.

TRY THIS…………….

x is directly proportional to y. x=20 while y=4. Find y when x is 200.

Ans. y=40