Mathematical Puzzles
Expert
2 min
A positive integer leaves remainder 2 when divided by 5 and remainder 3 when divided by 7. What is the smallest such integer?
Hint
List numbers that leave remainder 2 when divided by 5.
Answer
17.
Explanation
Numbers congruent to 2 modulo 5 are 2, 7, 12, 17, ... Among these, 17 leaves remainder 3 when divided by 7.
Step-by-Step Solution
2 mod 5 = 2
7 mod 5 = 2
12 mod 5 = 2
17 mod 5 = 2
17 mod 7 = 3
Therefore the answer is 17.
7 mod 5 = 2
12 mod 5 = 2
17 mod 5 = 2
17 mod 7 = 3
Therefore the answer is 17.