it takes bill 4hrs to make a ball and igor 12hours,how long if they work together will it take to create one ball

Question

it takes bill 4hrs to make a ball and igor 12hours,how long if they work together will it take to create one ball

Answer 1

This is a "work" word problem, and there are many different ways to solve it, but the easiest doesn't involve any complicated variables or arithmetic.

First, convert how much Bill and Igor can do in the given hours (4 and 12 respectively) to how much they can do in ONE hour.

If Bill takes 4 hours to make a ball, that means he can make 1/4 of a ball in one hour.

If Igor takes 12 hours to make a ball, that means he can make 1/12 of a ball in one hour.

To find their combined work, add 1/4 and 1/12. You can add them by finding the common denominator (which is 12), giving you 3/12 and 1/12, which add up to 4/12, or 1/3.

That means that together, they can make 1/3 of a ball in one hour. Your final answer, then, is that it takes them 3 hours to make a ball if they work together.

Answer 2

I like Jonathan explanation.

Here is different approach to solution.

In 12 hours Igor can make 1 ball and Bill can make 12÷4=3 balls.

Together they can make 1+3=4 balls in 12 hours.

It takes them 12÷4=3 hours to make 1 ball.

Best Wishes