Two pies A and B can fill a tank in 30 minutes and 45 minutes respectively. Both pipes are opened. The tank will be filled in just 20 minutes, if the pipe B is turned off after :

Explanation

Let pipe B be turned off after minutes Part filled by (A + B) in min. + part filled by A in (20-x)min. = 1 5✪✪ ✁✁ = 10 So X=15 minutes 90 30 3026. In a voyage of 600km, a ship was slowed down due to bad weather and storm in Ocean. Its average speed for the trip was reduced by 200 km/hr, and the time of trip increased by 30 minutes. The duration of the voyage is: (a) 1 hour (b) 2 hour (c) hour (d) hour (e) hour Ans.(a) Sol. Let the duration x be hours600 600 =200 , so x=1 hour ✢ 1 ✂✂ ☎☎+ 2