Answer:
Your friends can clap their hands 245 times in 1.75 minutes.
Explanation:
First of all, you should know how many seconds represents 1.75 minutes, because the amount of applause your friends can make is in that measure of time. In order to make this conversion, a simple rule of three is made, knowing that 1 minutes is 60 seconds:
If 1 minute is 60 seconds, how many seconds are 1.75 minutes?
![(1.75minutes*60seconds)/(1minute) =105 seconds](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2pgylkaq990aqfjbd8zohfh5j1donm813c.png)
Knowing that your friend can clap his hands 28 times in 12 seconds and knowing that 1.75 minutes is 105 seconds, you can perform a rule of three again:
If they can clap their hands 28 times in 12 seconds, how many applause can they make in 105 seconds?
![(105seconds*28applause)/(12) =245 applause](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5v51e12j1fycvwlt619f06wlwavw8h5wq6.png)
Then your friends can clap their hands 245 times in 105 seconds, which is 1.75 minutes.