Problema Solution

If martha the light house blinks every 5 seconds and billy the light house blinks every 8 seconds how many times will they blink at the same time in the next 6 minutes

Answer provided by our tutors

Least Common Multiple of 5 and 8 is 40


6 min = 6*60 = 360 seconds


lets assume that martha and billy blink together at the start that is in the 0 second thus


they will blink together in the 40 second and every multiple of 40 that is less than 360 that is


0

1*40 = 40

2*40 = 80

3*40 = 120

4*40 = 160

5*40 = 200

6*40 = 240

7*40 = 280

8*40 = 320

9*40 = 360


in the next 6 minutes they will blink together 10 times.