Which of the following numbers must be added to 5678 to give a remainder of 35…
2025
Which of the following numbers must be added to 5678 to give a remainder of 35 when divided by 460?
- A.
980
- B.
955
- C.
797
- D.
618
Attempted by 569 students.
Show answer & explanation
Correct answer: C
Compute the current remainder: 5678 − 460×12 = 5678 − 5520 = 158.
We need a number x so that (158 + x) ≡ 35 (mod 460).
Solve the congruence: x ≡ 35 − 158 ≡ −123 ≡ 337 (mod 460). The smallest positive solution is 337.
Any x of the form 337 + 460k (k an integer ≥ 0) will give remainder 35. In particular, 797 = 337 + 460, so adding 797 works.
Answer: 797