Hi there!
Isa finished 30% of his homework in 27 minutes. Therefore, she must complete another 70% of her homework.
To find the amount of time it costs for Isa to complete 10% of her homework, we must divide both sides of the equation by 3.
10% of her homework takes her 9 minutes.
Now we can easily find the amount of time is costs her to finish the other 70% of her homework, we must multiply our found amount of time by 7.
10% of the homework takes 9 minutes.
70% of the homework takes 63 minutes.
Therefore, the answer is 63 minutes.
~ Hope this helps you!