The number of ways of selecting two numbers from the set {1, 2, …,12} whose sum is divisible
The number of ways of selecting two numbers from the set {1, 2, …,12} whose sum is divisible
The number of permutations of the letters of the word HINDUSTAN such that neither the pattern ‘HIN’ nor ‘DUS’ nor ‘TAN’ appears, are
The number of permutations of the letters of the word HINDUSTAN such that neither the pattern ‘HIN’ nor ‘DUS’ nor ‘TAN’ appears, are
A credit card number has 5 digits (between 1 to 9). The first two digits are 12 in that order, the third digit is bigger than 6, the forth is divisible by 3 and the fifth digit is 3 times the sixth. How many different credit card numbers exist?
A credit card number has 5 digits (between 1 to 9). The first two digits are 12 in that order, the third digit is bigger than 6, the forth is divisible by 3 and the fifth digit is 3 times the sixth. How many different credit card numbers exist?
In a workshop there are 4 kinds of beds, 3 kinds of closets, 2 kinds of shelves and 7 kinds of chairs. In how many ways can a person decorate his room if he wants to buy in the workshop one shelf, one bed and one of the following: a chair or a closet?
In a workshop there are 4 kinds of beds, 3 kinds of closets, 2 kinds of shelves and 7 kinds of chairs. In how many ways can a person decorate his room if he wants to buy in the workshop one shelf, one bed and one of the following: a chair or a closet?
In a hockey tournament, a total of 153 matches were played. If each team played one match with every other team, the total number of teams that participated in the tournament were
In a hockey tournament, a total of 153 matches were played. If each team played one match with every other team, the total number of teams that participated in the tournament were
Danny, Doris and Dolly flipped a coin 5 times and each time the coin landed on “heads”. Dolly bet that on the sixth time the coin will land on “tails”, what is the probability that she‟s right?
Danny, Doris and Dolly flipped a coin 5 times and each time the coin landed on “heads”. Dolly bet that on the sixth time the coin will land on “tails”, what is the probability that she‟s right?
The number of flags with three strips in order that can be formed using 2 identical red, 2 identical blue and 2 identical white strips is
The number of flags with three strips in order that can be formed using 2 identical red, 2 identical blue and 2 identical white strips is
Out of a box that contains 4 black and 6 white mice, three are randomly chosen. What is the probability that all three will be black?
Out of a box that contains 4 black and 6 white mice, three are randomly chosen. What is the probability that all three will be black?
Three people are to be seated on a bench. How many different sitting arrangements are possible if Erik must sit next to Joe?
Three people are to be seated on a bench. How many different sitting arrangements are possible if Erik must sit next to Joe?
The probability of pulling a black ball out of a glass jar is 1/X. The probability of pulling a black ball out of a glass jar and breaking the jar is 1/Y. What is the probability of breaking the jar?
The probability of pulling a black ball out of a glass jar is 1/X. The probability of pulling a black ball out of a glass jar and breaking the jar is 1/Y. What is the probability of breaking the jar?
In a box there are A green balls, 3A + 6 red balls and 2 yellow ones. If there are no other colors, what is the probability of taking out a green or a yellow ball?
In a box there are A green balls, 3A + 6 red balls and 2 yellow ones. If there are no other colors, what is the probability of taking out a green or a yellow ball?
Number of positive integers n less than 15, for which n! + (n+1)! + (n+2)! is an integral multiple of 49, is
Number of positive integers n less than 15, for which n! + (n+1)! + (n+2)! is an integral multiple of 49, is
In a deck of cards there are 52 cards numbered from 1 to 13. There are 4 cards of each number in the deck. If you insert 12 more cards with the number 10 on them and you shuffle the deck really good, what is the probability to pull out a card with a number 10 on it?
In a deck of cards there are 52 cards numbered from 1 to 13. There are 4 cards of each number in the deck. If you insert 12 more cards with the number 10 on them and you shuffle the deck really good, what is the probability to pull out a card with a number 10 on it?
If nPr = nPr+1 and nCr = nCr-1, then (n, r) are
If nPr = nPr+1 and nCr = nCr-1, then (n, r) are
In how many ways can we distribute 5 different balls in 4 different boxes when order is not consider inside the boxes and empty boxes are not allowed
In how many ways can we distribute 5 different balls in 4 different boxes when order is not consider inside the boxes and empty boxes are not allowed
The sum of the factors of 7!, which are odd and are of the form 3t + 1 where t is a whole number, is
The sum of the factors of 7!, which are odd and are of the form 3t + 1 where t is a whole number, is
The number of diagonals that can be drawn by joining the vertices of an octagon is
The number of diagonals that can be drawn by joining the vertices of an octagon is
In jar A there are 3 white balls and 2 green ones, in jar B there is one white ball and three green ones. A jar is randomly picked, what is the probability of picking up a white ball out of jar A?
In jar A there are 3 white balls and 2 green ones, in jar B there is one white ball and three green ones. A jar is randomly picked, what is the probability of picking up a white ball out of jar A?
The number of ordered triplets (a, b, c), a, b, c \(\in\) N, such that a + b + c \(\in\)20 is
The number of ordered triplets (a, b, c), a, b, c \(\in\) N, such that a + b + c \(\in\)20 is
There are 18 balls in a jar. You take out 3 blue balls without putting them back inside, and now the probability of pulling out a blue ball is 1/5. How many blue balls were there in the beginning?
There are 18 balls in a jar. You take out 3 blue balls without putting them back inside, and now the probability of pulling out a blue ball is 1/5. How many blue balls were there in the beginning?