Question

Tennis ball machine can launch 60 tennis balls in 12 minutes. At this rate, how many tennis balls can it launch in 2 hours?

Answer 1

Hint: In this problem, we have to find how many tennis balls can be launched in 2 hours if a tennis ball machine can launch 60 tennis balls in 12 minutes. We can first divide the given number of tennis balls to the given time, we will get the number of balls launched in a minute, so that we can find the number of balls that can be launched in 2 hours, by multiplying the time to the number of balls launched per minute.

Complete step-by-step solution:
We know that a tennis ball machine can launch 60 tennis balls in 12 minutes.
we can now write it as,
$$\Rightarrow {\displaystyle \frac{60}{12}}={\displaystyle \frac{5}{1}}$$
We can see that in the above step, 5 balls can be launched in 1 minute.
Now we have to find the number of balls that can be launched in 2 hours.
We know that 1 hour = 60 minute, whereas 2 hour = 120 minutes.
We can now multiply the number of balls launched in one minute and 120 minutes, we get
$$\Rightarrow 120\times 5=600$$
Therefore, 600 tennis balls can be launched in 2 hours.

Note: We also have another method to solve this problem.
We know that there are 120 minutes in 2 hours and 10 sets of 12 minutes in 120 minutes.
We can now see that, 10 sets of 60 balls can be launched,
$$\Rightarrow 10\times 60=600$$
Therefore, 600 tennis balls can be launched in 2 hours.