Answer:
378
Step-by-step explanation:
It will also be a multiple of 21 .
As it is divisible by 3 the first possibility is 366 so:-
364 + n = 21m
where n = 2,5,8,11,14...
Trying each number in turn we get:-
364 + 14 = 21m
21m = 378
m = 18
so the answer is 378
