Question

If y varies directly as x and y = 16 when x = 25, find x when y = 40.*

Answer 1

62.5

Explanation:

y ∝ x

y= kx

y=16,x=25

just substitute

y=kx

16= k × 25

16= 25K

k=16/25

y = 16/25x

when y=40 x= ?

using the formula

y = 16/25x

40=16/25 × x

cross multiply

40×25=16x

1000=16x

x=62.5