Answer:
D) The value of u is 4.68 when v= 7.8 .
Explanation:
Two quantities P and Q are said to be in proportion if one quantity is always a multiple of the other quantity.
or, P ∝ Q ⇒ P = k Q for some arbitrary constant k.
Here, u varies directly with v
⇒ u = k v
Now, k = 0.6 and v = 7.8
So, u = k v
= (0.6) x (7.8) = 4.68
or, u = 4.68
Hence, the value of u when v= 7.8 is 4.68.