Level 2
The average cost of 5 books is $30.
After another book that costs $90 is added,
  1. What is new total cost of all the books?
  2. What is new average cost of all the books?
3 m
Level 2
The average cost of 5 books is $30.
After a book that costs $60 is removed,
  1. What is new total cost of all the remaining books?
  2. What is new average cost of all the remaining books?
3 m
Level 2
The average cost of 5 books is $30.
After 2 books are removed,
the average cost of the remaining books is $20.
  1. What is the total cost of the 2 books that are removed?
  2. What is the average cost of the 2 books that are removed?
3 m
Level 2
The average cost of 5 books is $50.
After 2 new books are added,
the average cost of all the books is $40.
  1. What is the total cost of the 2 books that are added?
  2. What is the average cost of the 2 books that are added?
3 m
Level 2
The average cost of three books is $30.
Two of the books cost $10 and $20.
What is the cost of the 3rd book?
2 m
Level 3
The average cost of some books is $75.
When another 3 books are added,
the total cost increases by $190.
The average cost becomes $70.
How many books are there in the end?
3 m
Level 3
The average cost of some books is $30.
When a book that costs $90 is added,
the average cost of the books becomes $40.
How many books are there in the end?
3 m
Level 3
The average cost of some books is $30.
When a book that costs $90 is removed,
the average cost of the books becomes $10.
How many books are there in the end?
3 m
Level 3
The average cost of some books is $30.
If 3 of the books are now each $15 more,
the average cost of the books becomes $35.
How many books are there altogether?
3 m
Level 3
The average cost of some books is $30.
If 3 of the books are now each $15 more and
2 of the books are now each $5 less,
the average cost of the books becomes $32.
How many books are there altogether?
3 m