What is (23 × 19) mod 5?

Modulo Arithmetic & Congruence · Question 23 of 97

Question 23

EasyOriginal question

What is $(23 \times 19) \bmod 5$ ?

2

Correct answerYour answer

3

Correct answerYour answer

4

Correct answerYour answer

12

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

$23 \bmod 5 = 3$ and $19 \bmod 5 = 4$ , so multiply the remainders: $3 \times 4 = 12$ .
$12 \bmod 5 = 2$ . Check: $437 = 5 \times 87 + 2$ .

Worth noting

12 is the product of the remainders before it was reduced modulo 5.

Ten questions from Modulo Arithmetic & Congruence, at your own pace.

Ten questions from Modulo Arithmetic & Congruence, at your own pace.