Which is the smallest number you should add to an odd number to make it even?

Find the HCF of 3, 7 and 15. 

(A) 7 

(B) 15 

(C) 3 

(D) 1 

Find the sum and check whether it is even or odd.

$2+3$

The sum of two odd numbers is an even number.

Write '$\mathrm{E}$' (for even) or '$\mathrm{O}$' (for odd) to the given number. Look at the digit in the ones place and decide.

$117$