LCM of 10, 15, 25 = 150When we drive 2641 by 150 the remainder is 91.But the remainder should be 7.So, the number to be subtracted from 2641 is 91 - 7 = 84.
Since the number is greater than the number obtained on reversing the digits, so the ten's digit is greater than the unit's digit.Let the ten's and unit's digits be 2x and x respectively.Then, (10 * 2x + x) - (10x + 2x) = 369x = 36x = 4Required difference = (2x + x) - (2x - x) = 2x = 8.
This is a simple division series. Each number is divided by 5. Rule = (1st number / 5 = 2nd number) (2nd number / 5 = 3rd number)....Now, (1000 / 5 = 200), (200 / 5 = 40), (40 / 5 = 8)...So answer is a = 8.