Question

Which of the following helps you to determine that 369 is divisible by 3?
a) The first digit is a 3.
b) 9 is divisible by 3.
c) 69 is divisible by 3.
d) 3+6+9 is divisible by 3.

Answer 1

to test if a number will be divisible by 3,
see if the sum of its digits is divisible by 3

Answer 2

ok!

Answer 3

why does it work ? you can ponder/google for a simple proof ! you can use the same logic for testing divisibility by 9, 11 and many others... good luck :)

Answer 4

thanks!!

Answer 5

np :)