If y varies directly with x, and y = 61 when x = 42, find y when x = 54 (consider integral value).
Answer & explanation
Correct answer: option 2
y ∝ x
y = kx (k is a constant)
or y/x = k
x : y
42 : 61 :: 54 : ?
y = $\frac{61\; \times\;54}{42}$
= 78
If y varies directly with x, and y = 61 when x = 42, find y when x = 54 (consider integral value).
Correct answer: option 2
y ∝ x
y = kx (k is a constant)
or y/x = k
x : y
42 : 61 :: 54 : ?
y = $\frac{61\; \times\;54}{42}$
= 78