A mixed doubles tennis game is to be played between two teams (each team consists of one male and one female). There are four married couples. No team is to consist of a husband and his wife.
What is the maximum number of games that can be played?
Let H be husband and W be wife The possible teams are (H1,W2), (H1,W3), (H1,W4) (H2,W1), (H2,W3), (H2,W4) (H3,W2), (H3,W1), (H3,W4) (H4,W2), (H4,W3), (H4,W1) ie., 12 teams or a max of 6 matches can be played.
How many 3-digit numbers can be formed from the digits 2, 3, 5, 6, 7 and 0, which are divisible by 5 and none of the digits is repeated?
A double Decker bus can accommodate 80 passengers 35 in upper deck and 40 in lower deck. In how many ways can a group of 80 passengers be accommodated if 5 refuse to sit in the lower deck and 10 refuse to sit in the upper deck
There are four different letters and four different letter boxes, in how many methods these letters can be dropped in the boxes, if all the four letters in a single box are not allowed?
How many squares can be formed in the following image by connecting four points of 8x8 grid?
