Question

5 bells struck at intervals of 6,8,9 &12 seconds. they struck simultaneously with a clock at 12 noon which strikes every hour. at what time will they again strike together with the clock? this is related to real numbers & HCF or LCM of numbers of class 10

Answer 1

Find the LCM of 6, 8, 9 and 12 which will be 72. Which means that after every 72 seconds all four bells will at the same time. So, the next bell at the same time will be 12:01:12.

Answer 2

Answer:

All the bells will strike together simultaneously at 01: 12 pm.

To find:

The time at which all the bells strike together

Solution:

Given that the bells strike at 6, 8, 9 &12 seconds

Take LCM of 6, 8, 9 &12

LCM of 6 =2×3

LCM of 8 = 2 ×2 × 2

LCM of 9 = 3 ×3

LCM of 12 =2×2×3

LCM (6 , 8, 9 and 12) =2^3×3^2=8×9=72

Thus, they strike simultaneously after 72 minutes which is equal to 1 hour and 12 minutes.

We have to go with minutes instead of seconds since it is given that the bells strikes simultaneously at one time for every hour.

Hence, after 1 hour and 12 minutes ahead of 12 noon, the bells strike simultaneously i.e., at 1: 12 pm.