Question

If R is inversely proportional to A, and R = 4 when A = 100, what is the value of R when A = 250 A : .625 B : 1.6 C : 10 D : 6,250

Answer 1

Answer: (b)

Step-by-step explanation:

Given

R is inversely proportional to A i.e

$R\propto \dfrac{1}{A}\\\\R=\dfrac{C}{A}\quad [\text{C=Constant}]$

when $R=4,\ A=100$

Insert the values to get C

$\Rightarrow 4=\dfrac{C}{100}\\\\\Rightarrow C=400$

When A=250

$\Rightarrow R=\dfrac{400}{250}\\\\\Rightarrow R=1.6$

option (b) is correct