If A varies directly as B, and A = 210 when B = 51, then find A when B = 136.

Correct option is B

Given:

A ∝ B (A varies directly as B)

A = 210 when B = 51

Find A when B = 136

Solution: 

A ∝ B 

A = kB 

210 = k(51) 

k = $$\frac{210}{51}$$​  

Now, 

A = $$\frac{210}{51} \times 136 = 560$$​​