A variable name in certain computer language must be either an alphabet or an alphabet followed by a decimal digit. The total number of different variable names that can exist in that language is equal to a. `280` b. `390` c. `286` d. `296`

In a certain game,each player scores either 2 points or 5 points.If n players score 2 points and m players score 5 points,and the total number of points scored is 50, what is the least possible difference between m and n? (a) 1 (b) 3 (c) 5 (d) 7

A person predicts the outcome of 20 cricket matches of his home team. Each match can result in either a win, loss, or tie for the home team. Total number of ways in which he can make the predictions so that exactly 10 predictions are correct is equal to a. ^20 C_(10)xx2^(10) b. ^20 C_(10)xx3^(20) c. ^20 C_(10)xx3^(10) d. ^20 C_(10)xx2^(20)

Assertion: The number of different number plates which can be made if the number plte contain three letters of the English alphabet followied by athree digit number is (26)^3xx(900) (if represents are allowed) Reason: The number of permutationis of n different things taken r at time when repetitios are allowed is n^r . (A) Both A and R are true and R is the correct explanation of A (B) Both A and R are true R is not te correct explanation of A (C) A is true but R is false. (D) A is false but R is true.