Answer:
43
Explanation:
The LCM of 14 and 21 is 42. This is the smallest number that can be divided by both 14 and 42 without leaving a remainder
Add 1 to this so that we get a remainder of 1 when divided by 14 or 21
__4__
14) 43
42
-------------
1
43 ÷ 14 => quotient 4 and remainder 1
__2__
21) 43
42
-------------
1
43 ÷ 21 => quotient 2 and remainder 1