Nicholas bought three business related books. his total bill was $150. if one book cost him 50% more than the other two books combined what was the price of this more expensive book?

90 - because you take  30 + 30 = 60 then you multiply it by .5 to ad the 50% more, then you add that to the original 60 to get the price of the more expensive book. you can check you work by adding them together 30+30+90=150.