The least number which when divided by 15 leaves a remainder of 5, when divided by 25, leaves a remainder of 15 and when divided by 35 leaves a remainder of 25 is
The least number which when divided by 15 leaves a remainder of 5, when divided by 25, leaves a remainder of 15 and when divided by 35 leaves a remainder of 25 is Correct Answer 515
Given:
The given number = 15, 25, and 35
Remainders = 5, 15, 25 respectively
Concept used:
LCM: Product of the greatest power of each prime factor, involved in the numbers.
HCF: Product of the smallest power of each common prime factor in the numbers.
The least number which when divided by a, b, c leaves remainder x, y, z respectively in each case such that
(a – x) = (b – y) = (c – z) = k
Number = lcm of (a, b, c) – k
Calculation:
15 = 3 × 5
25 = 5 × 5
35 = 5 × 7
LCM (45, 25, 35) = 3 × 52 × 7 = 525
Since the difference between divisor and remainder is 10.
Thus, least number = 525 - 10 = 515
Hence, the least number is 515.