A watch manufacturing company is testing watch alarms. They program alarms of all the watches to
beep simultaneously. The alarms start beeping at intervals of 5, 8, 10, 15 and 21 seconds respectively.
In an hour, how many times do the alarms beep together?
Answers
Step-by-step explanation:
at second second it will interval of by watch
Given:
The intervals=5, 8, 10, 15 and 21 seconds
To find:
The number of times the alarms beep together in an hour
Solution:
The number of times the alarms beep together in an hour is 4.
We can find the number by following the given process-
We know that the LCM of intervals of all the alarms needs to be calculated to obtain the number of times all the alarms will beep together.
The intervals of all alarms: 5, 8, 10, 15, 21
We will calculate the LCM of 5, 8, 10, 15, 21=840
So, all the alarms will beep together after every 840 seconds.
We need to obtain the number of times they will beep together in an hour.
The number of seconds in an hour=3,600
The number of times all the alarms will beep together=Total seconds in an hour/ Seconds after which they beep together
=3,600/840
=4.28
Since it is not completely divisible, the alarms will beep together 4 times in an hour and again after the hour is finished.
Therefore, the number of times the alarms beep together in an hour is 4.