Jodie buys 12 cans of cola. There are 330 m/of cola in each can. l
Rob buys 4 bottles of cola.
There is 1 litre of cola in each bottle.
Rob buys more cola than Jodie.
How much more?

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )