If it takes a tub 4 minutes to drain 5/7 of its content, how much more time will it take for the tub to be empty?  Choose the correct option: A) 48 seconds B) 1 minute , 12 seconds C) 1 minute , 36 seconds D) 2 minutes , 14 seconds E) 4 minutes , 12 seconds

Rationale: "if 5 / 7 of tub ' s content is drained 2 / 7 th of tub still needs to be drained . if it takes 4 minutes to drain 5 / 7 th of tub it takes 4 * ( 7 / 5 ) minutes to drain the entire tub and 4 * ( 7 / 5 ) * ( 2 / 7 ) min to drain 2 / 7 th of the tub which is 8 / 5 minutes or 1 3 / 5 minutes or 1 minute 36 seconds so answer is c"
Answer: C