The total number of five digit numbers formed by 1, 2, 3, 4 and 5 (without repetition) = ∟5 =120 A number is divisible by 4 if the last two digit number (i.e. tens and unit place) is divisible by 4. ∴ The last two digit number must be: 12, 24, 32 and 52. With last two digits 12, the other three places can be arranged in 3! (= 6) ways. ∴ The number of favourable cases = 3! × 4 = 24 ∴ Probability =