Question

23. The least of 4 digit number which is exactly divisible by 8, 15 and 21 is​

Answer 1

Answer:

The smallest 4-digit =1000

Now L.C.M of 12,15,20and35

2∣12,15,20,35

2∣6,15,20,35

3∣15,5,35

5∣1,5,5,35

7∣1,1,1,1

1,1,1,1

L.C.M.=2×2×3×5×7=420

We divided 1000 by 420

420)1000(2

−840

160−Remainder

∴ The least 4−digit number that is exactly divisible by 12,15,20 and 35

=1000+(420−160)

=1000+260=1,260