# Thread: Inverse Proportion. explanation needed

1. ## Inverse Proportion. explanation needed

Hi im studying for an exam and i have lost my sheet explaining how to do inverse proportion.

I have the question: A farmer has enough grain to feed 50 cattle for 10 days. He sells 10 cattle. For how many days will the grain last now?

The first time i went through i got the answer 12.5 days and i now do not know how to get back to that answer.

2. Originally Posted by Boredom
Hi im studying for an exam and i have lost my sheet explaining how to do inverse proportion.

I have the question: A farmer has enough grain to feed 50 cattle for 10 days. He sells 10 cattle. For how many days will the grain last now?

The first time i went through i got the answer 12.5 days and i now do not know how to get back to that answer.

There are (10)(50) = 500 units of grain.

500/40 = 12.5 => 12.5 days.

3. Hmm so simple.

Thanks

4. Originally Posted by Boredom
Hi im studying for an exam and i have lost my sheet explaining how to do inverse proportion.

I have the question: A farmer has enough grain to feed 50 cattle for 10 days. He sells 10 cattle. For how many days will the grain last now?

The first time i went through i got the answer 12.5 days and i now do not know how to get back to that answer.