Question

A radio station plays one song once every 4 days. Another radio station plays the same song once every 8 days. How many times in 30 days will both radio stations play the same song on the same day?

Answer 1

To find the number of days on which both the stations played the same song we need to find the common multiples of both the numbers.
Let us write the multiples of 4 and 8.
Here we could have written multiples greater than 30 but since we need to count the number of days within 30 days only we wrote all the multiples till 30 only.
So on 8th 16th and 24th day both the stations will play the same song.
That is 3 times in 30 days.