The variable x varies directly as y and x = 80 when y = 160, What is y when x is 64.
If x varies directly as y.
∴ 
If x = 80 and y = 160 …(i)
∴ 
⇒ 
When x = 64, then from Eq. (i)
⇒ y = 64 × 2 = 128
64
The variable x varies directly as y and x = 80 when y = 160, What is y when x is 64.
If x varies directly as y.
∴
If x = 80 and y = 160 …(i)
∴
⇒
When x = 64, then from Eq. (i)
⇒ y = 64 × 2 = 128