Help with maths question please

[fabs]

Two different clocks show the time 3o'clock.

The first gains 5 minutes per hour and the second gains 20 minutes per hour.

How long will it be in hours before both clocks look as though they show the same time?

[yoyo123]

diagrams are good for this type of question.
Try timelines, both starting at 3 O clock, one going up in 5s and the other in 20s , where do they co-incide?

You can do it more “mathematically”, but for KS2, I love diagrams

[fabs]

Thank you yoyo. I have found the answer to be 48 hours but how can I reach the answer in a mathematical way?

[Qeb2019]

Two different clocks show the time 3o'clock.

The first gains 5 minutes per hour and the second gains 20 minutes per hour.

How long will it be in hours before both clocks look as though they show the same time?

Every hour the second clock goes 15 minutes faster than the first. In order to show same time the second clock needs to go 1 more circle than the first. 1 circle is 12 hours=12x60=720minutes. Therefore it needs 720/15=48 hours.

Hope that help.

[fabs]

Two different clocks show the time 3o'clock.

The first gains 5 minutes per hour and the second gains 20 minutes per hour.

How long will it be in hours before both clocks look as though they show the same time?

Every hour the second clock goes 15 minutes faster than the first. In order to show same time the second clock needs to go 1 more circle than the first. 1 circle is 12 hours=12x60=720minutes. Therefore it needs 720/15=48 hours.

Hope that help.

Genius! Hope you don't mind me passing it off as my own?!