UPSC Prelims 2016 · CSAT (Paper 2) · Q72

General Mental Ability

Hard · Permutations with constraints

How many 4-digit numbers can be formed using the digits 1, 2, 3, 4 and 5 (each digit used at most once in a number) such that the number is divisible by 5 and the digit 1 does not occupy the first position?