Nine lollies cost less then $10 while ten lollies cost more than $11. How much does each lolly cost?
There is no answer to that. 11/10 = 1.1, and 10/9 = 1.1
Increasing the price of a lolly would mean that the cost would go above $10 and $11, whilst decreasing the price would mean both go below $10 and $11