Two pipes A and B can fill a tank in 10 and 20 minutes respectively.If both pipes are opened simultaneously,after how many minutes should pipe B be closed so that the tank is full in 8 minutes?
A. 3 min
B. 4 min
C. 2 min
D.5 min
Out of 8 crew members 3 particular members can sit only on the left side.Another 2 particular members can sit on the right side.Find the number of ways in which the crew can be arranged so that four men can sit on each side
"The gaming of numbers is called maths.So participate in this wonderful game and explore in it,learn in it and enjoy in it.Then only you can pass in this wonderful game."
Kumar Purnendu
God does not care about our mathematical difficulties; He integrates empirically.