3 / 40: remainder = 3
13.3333
3, remainder 40
40.2143
No. Add the digits of the dividend and if that is divisible by 3 then the original number is divisible by 3; if not, its remainder when divided by 3 gives the remainder when the original number is divided by 3: 1 + 2 + 1 = 4 which gives a remainder of 1 when divided by 3, so 121 divided by 3 gives a remainder of 1. (121 = 40 x 3 + 1)
3 / 40: remainder = 3
13.3333
3, remainder 40
3.15
40.2143
8.6
4.4444
3.0769
No. Add the digits of the dividend and if that is divisible by 3 then the original number is divisible by 3; if not, its remainder when divided by 3 gives the remainder when the original number is divided by 3: 1 + 2 + 1 = 4 which gives a remainder of 1 when divided by 3, so 121 divided by 3 gives a remainder of 1. (121 = 40 x 3 + 1)
1
It is 6 with a remainder of 4
40 divided by 6 is 6 with remainder 4.