Level 3
The average mass of a group of girls is 45 kg. If one more girl who weighs 75 kg joins the group, the new average mass of the group will become 48 kg. Find the total number of girls in the group.
3 m
Level 3
The auditorium had 1050 seats. There were 25% fewer $40-seats than $5-seats. 50% of the $5-seats and some $40-seats were sold. A total of $16180 was collected. How many seats were unsold?
4 m
Level 3
The average number of pages Joan read in a certain number of days was 15. In the next four days, Joan read another 88 pages. As a result, the average number of pages she read increased to 17. How many days did Joan read in total?
3 m
Level 3
Luis drew lines to form triangles and stars. He drew 7 more triangles and stars. The number of lines drawn for the triangles was the same as the number of lines drawn for the stars. What fraction of the shapes that Luis had drawn were stars?
3 m
Level 3
Entrance tickets to the concert are $8 each for adults. The ticket for a child costs 25% less. Last Sunday, 10% of the tickets sold were for children and the total sales of the tickets was $3900. How many of the tickets sold were for adults?
4 m