Question

Nine students can make a poster in 10 hours how many students join them so that they can all together make this poster in six hours

Answer 1

there is not enough information

Answer 2

Answer:

If 9 students make the poster in 10 hours
Then it would take 1 student 90 hours to make 1 poster
Therefore you do 90 hours/6hours to get 15
So you'd need 15 students to make the poster in 6 hours
Which means 6 more students would need to join them

Explanation: hope this helps you