Question

The variable y is directly proportional to the variable x. If y = 32 when x = 20, what is the value of x when y = 40?

Answer 1

Answer:

The Correct option is C ) 25

Therefore the value of x is 25 when y =40.

Step-by-step explanation:

Given:

Variable 'y' is directly proportional to the variable 'x'.

$\therefore y=kx$     ......Direct Variation

Where,

k = Constant of proportionality

To Find:

value of x = ? when y = 40

Solution:

First we need to find Constant of proportionality

When x = 20 and y = 32

Substituting the values we get

$32=k\times 20\\k=\dfrac{32}{20}=1.6\\\\k=1.6$

Now when k =1.6 , y = 40 then x will be

$40=1.6\times x\\\\x=\dfrac{40}{1.6}=25\\\\x=25$

Therefore the value of x is 25 when y =40.