Question
The average cost of 4 colouring books is $80.
The average cost of 3 colouring books is $10.
What is the cost of 4th book?
2 m

Click button first when a symbol is required. X

The average cost of 4 colouring books is $80.
The average cost of 3 colouring books is $10.
What is the cost of 4th book?