Question. On average, the bottle-nosed dolphin comes up for air once every three minutes; the beluga whale, a close relative, comes up for air on average once every six minutes. The number of times a bottle-nosed dolphin would come up for air in a 24 hour period is approximately what percent greater than the number of times a beluga whale would come up for air in that same period?
Options:
(A) 25%
(B) 50%
(C) 75%
(D) 100%
(E) 150%
Answer. (E)
What step-by-step reasoning justifies that answer?
Reasoning: Dolphin once in 3 min;
Beluga once in 6 min;
So, dolphin comes up 2 times frequently than beluga, which is 150% (6-3)/2*100.