Level 3
The average cost of some books is $30.
After 2 new books are added,
it adds another $10 to the total cost.
As a result, the average cost of all the books decreases to $20.
How many books are there at first?
Level 2
Liam and Tim share a bunch of chikoos in the ratio 5 : 3. If Liam gives Tim 23 chikoos from his share, they will have the same number of chikoos. How many chikoos does Liam have at first?
Level 2
The ratio of the number of blue stickers to red stickers is 5 : 2.
After Adam buys 10 blue stickers and 40 red stickers,
there is an equal number of blue stickers and red stickers.
How many stickers does Adam have now?
Level 2
The ratio of the number of blue stickers to red stickers is 5 : 2.
After Adam gives away 10 blue stickers and 40 red stickers,
there is an equal number of blue stickers and red stickers.
How many stickers does Adam have now?
Level 2
The ratio of the number of blue stickers to red stickers is 5 : 2.
After Adam gives away 10 blue stickers and buys another 20 red stickers,
there is an equal number of blue stickers and red stickers.
How many stickers does Adam have now?
