Multiple choice

A number which when divided by 10 leaves a remainder of 9, when divided by 9 leaves a remainder of 8, and when divided by 8 leaves a remainder of 7, is:

  1. 1539

  2. 539

  3. 359

  4. 1359

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A number that leaves remainder n-1 when divided by n has the form N = k × LCM(10,9,8) - 1. LCM(10,9,8) = 360. Testing k=1 gives 359, which satisfies all conditions: 359 ÷ 10 = 35R9, 359 ÷ 9 = 39R8, 359 ÷ 8 = 44R7.