Question

2. Christine can bake cookies for a school bake sale to

raise money for the school's soccer team in 9 hours. If
her friend, Emily, on the soccer team helps her, it only
takes 4 hours. How long would it take Emily to bake the
cookies alone?

Answer 1

the time taken by Emily to bake the cookies alone is 7.2 hours

Explanation:

The time taken by Emily to bake the cookies alone is shown below:

Given that

Christine can bake cookies in 9 hours

And, if her friend Emily is also helps her so it only takes 4 hours to bake the cookies

Now based on the above information

`(1)/(9) + (1)/(x) = (1)/(4) \\\\(1)/(x)= (1)/(4) - (1)/(9) \\\\(1)/(x)= (9 - 4)/(36) \\\\(1)/(x)= (5)/(36) \\\\x = (36)/(5)\\\\= 7.2 hours`

Hence, the time taken by Emily to bake the cookies alone is 7.2 hours