Question

Find the least number which leaves a remainder 7 when it's divided by any one of the number : 20, 30 and 40 .​

Answer 1

Find LCM first

2 |20,30,40

2 |10,15,20

2 |5,15,10

3 |5,15,5

5 |5,5,5

. |1,1,1

• 2×2×2×3×5=120

Now remainder is 7

The number is 120+7=127