Question

Light A flashes every 8 seconds

Light B flashes every 20 seconds
Both lights flash at the same time
Work out how long it will take for both lights to flash at the same time again

Answer 1

Answer:40sec

Step-by-step explanation:you get the lcm of the seconds

2 8 20

2 4 10

2 2 5

5 1 5

1 1

2×2×2×5×1=40sec

Answer 2

8x5=40
20x2=40


They will both flash at the same time at 40 seconds !