What does the sentence mean?

[dido4]

In countries like Tanzanian, water is hard to get, and the job of collecting water falls on women's shoulders. Girls are often kept from school to collect water while their brothers stay at school studying.
Studies show Tanzanian girls who live 15 minutes from clean water spend 12% more time at school than those who live half an hour away.
More time spent collecting water means less time for learning.

Q: I don't understand the sentence underlined. What does it mean?

Thank you.

 

[SoothingDave]

What part don't you understand? Girls who live closer to a source of water have more time to go to school.

 

[Raymott]

If you live 15 minutes from clean water, that means that it takes you 15 minutes to walk to where there is clean water (and I'd guess another 15 minutes to walk home with it).

 

[tedmc]

There is no piped water in those backward African countries and girls are expected to carry water collected from the wells. The further they live, the more time they have to spend doing that.

 

[MikeNewYork]

The country is Tanzania, not Tanzanian.

 

[Matthew Wai]

The farther they live away from water, the more time they spend getting water and the less time they spend at school.

I am not a teacher.

 

[emsr2d2]

There is no piped water in those backward African countries and girls are expected to carry water collected from the wells. The further they live, the more time they have to spend doing that.

I'm not sure that "backward" is an acceptable (PC) way of describing entire countries these days.

 

[Matthew Wai]

I consider 'developing' an alternative, but I am not a teacher.