There are 20 balls. The balls are numbered consecutively starting from anyone of the numbers from 1 to 20. For any case, the sum of the numbers on all the balls will be a/an

6 balls marked as 1,2,3,4,5 and 6 are kept in a box. Two players A and B start to take out 1 ball at a time from the box one after another without replacing the ball till the game is over. The number marked on the ball is added each time to the previous sum to get the sum of numbers marked on the balls taken out. If this sum is even, then 1 point is given to the players. the first player to get 2 points is declared winner. at the start of the game, the sum is 0. if A starts to take out the ball, find the number of ways in which the game can be won.

6 balls marked as 1,2,3,4,5 and 6 are kept in a box. Two players A and B start to take out 1 ball at a time from the box one after another without replacing the ball till the game is over. The number marked on the ball is added each time to the previous sum to get the sum of numbers marked on the balls taken out. If this sum is even, then 1 point is given to the players. the first player to get 2 points is declared winner. at the start of the game, the sum is 0. if A starts to take out the ball, find the number of ways in which the game can be won.

If a bag containing red and white balls, half the number of white balls is equal to one - third the number of red balls. Thrice the total number of balls by 6. How many balls of each colour does the bag contain ?

Find the number of selections of 10 balls from unlimited number of red black and white balls.

A bag contains in all 80 balls. Some of them are white, some are blue and some are red. The number of white balls is 12 times the number of blue balls. The number of red balls is less than the number of white balls but more than the number of blue balls. If one ball is selected at random from the bag, what is the probability that it is red ?