Answer:
40
Step-by-step explanation:
5 x 8 = 40
8 x 5 = 40
4 x 10 = 40
5: 5, 10, 15, 20, 25, 30, 35, 40
8: 8, 16, 24, 32, 40
4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40
