Question

40. A tap having diameter d' can empty a tank in 40 minutes. How long another tap having diameter 2d' take to
empty the same tank?
a) 5 min b) 20 min c) 10 min d) 40 min e) None of these​

Answer 1

Answer:

e) None of these​

Step-by-step explanation:

1d= 40 min

then,2d=80

so it will take 80 min

Answer 2

Answer:

b) 20 min

Step-by-step explanation:

d' = 40 min

2d' = 40/2

     = 20 min

Hence Proved