What is 20 mod 9?

How to compute 20 mod 9?

The simplest approach is to use the "mod" operator (often denoted as "%" in many programming languages), but you could do it manually in the following way:

$\mathrm{Remainder}=N-(M\times \lfloor \frac{N}{M}\rfloor )$

(where N is the dividend, M is the divisor and $\lfloor \frac{N}{M}\rfloor$ represents the integer part of the quotient)

1. 20 / 9 = 2.2222222222222
2. ⌊2.2222222222222⌋ = 2 (We only keep the integer part)
3. 9 × 2 = 18
4. 20 - 18 = 2 (Subtracting gives us the remainder)

In short: 20 − (9 × ⌊20 / 9⌋) = 2

Is 20 divisible by 9?

A number is said to be divisible by another number, if the remainder of the division is zero.

Given that the result of 20 mod 9 is 2, this indicates that dividing 20 by 9 leaves a remainder of 2. Therefore, no, since the remainder isn't zero, 20 is not divisible by 9.