Question

Find least no which when divided by 20, 25, 30, 36 leaves a remainder 4 in each case

Answer 1

20=5 and 36=9 srry then rest i do not know

Answer 2

Sorry but it's not possible (if only whole numbers are asked) that a single number leaves a remainder of 4 in each case but if your are looking for different numbers for each one​ then:
For 20=8(8×2)
25=7(7×3)
30=13(13×2)
36=16(16×2)
I hope you found it helpful......