Question

one tap fills a tank in 20 minutes and another tap fills it in 12 minutes. the tank being empty and if both taps are opened together, in how many minutes the tank will be full?

Answer 1

I hope you understand my writing

Answer 2

Answer:

The tank will be full in 7.5 minutes if both taps are opened together.

Step-by-step explanation:

Tap 1 fills a tank in 20 minutes

Tap 1 fills part of tank in 1 minute = $\frac{1}{20}$

Tap 2 fills a tank in 12 minutes

Tap 2 fills part of tank in 1 minute = $\frac{1}{12}$

If they both are opened together , So, Part of tank filled in 1 minute:

= $\frac{1}{20}+\frac{1}{12}$

= $\frac{2}{15}$                          

So, They both filled  $\frac{2}{15}$ part of tank in minute = 1

So, They both filled  whole tank in minute = $\frac{1}{\frac{2}{15}}$

                                                                      = $\frac{15}{2}$

                                                                      = $7.5$

Hence the tank will be full in 7.5 minutes if both taps are opened together.