Bill’s Burger shop’s profit from the sale of its famous “Billy Burger” was what percent greater this year than it was last year?
(1) The ratio of this year’s “Billy Burger” revenue to last year’s was 3 to 2
(2) The price of the “Billy Burger” was the same this year as it was last year
Solution: In order to know the percent change in profit for two years of Billy Burger sales you will need to know either the profit from both years or the relative change in both revenue and expenses.
Statement (1) gives us the relationship between the revenues but tells us nothing about the costs. Insufficient.
Statement (2) gives us information about the revenue per unit but tells us nothing about how many were sold nor the cost per unit. Insufficient.
Statement (1) + Statement (2) Putting them together you are still missing information on the expenses so you have no way to relate the profit’s from the two years.