Question

five Bells begin tolling together and toll at intervals of 2 4 6 8 10 and 12 seconds respectively .In 45 minutes how many times do they toll together?​

Answer 1

Answer:

Five bells commence tolling together and tolls at intervals 3 , 6 , 9, 12 , 15 sec respectively.

Toll altogether at LCM of {3, 6, 9, 12, 15}

Prime factor of 3 = 1 × 3

Prime factor of 6 = 1 × 2 × 3

Prime factor of 9 = 1 × 3 × 3 0

Prime factor of 12 = 1 × 2 × 2 × 3

Prime factor of 15 = 1 × 3 × 5

Toll altogether = 1 × 2 × 2 × 3 × 3 × 5

= 4 × 9 × 5 = 4 × 45 = 180 sec = 3min

Number of times do they toll altogether

= 45 min/3min

= 15

Hence, number of time do they toll altogether is 15

Hope it helps :)