I want to know how to do these 2 types of sums in an easier method......

1. The smallest 4 digit number exactly divisible by 12, 15, 20 and 35.

2. The least number when divided by 7, 10, 15 and 21 leaves 5, 8, 13 and 19 respectively as remainders.

Thanks

MoniMini @(^_^)@