Question

Someone help me with number 7 please!!

Answer 1

P is inversely proportional to V  
That is P = k/V  where k is some constant.
Plug in the given values for P and V:-

25 = k/400   giving k =  10,000

so the relation is P = 10,000 / V

when V = 200 ,   200P = 10,000

Its A