At a store, Mimi paid Tk. 100 for 5 oranges. If oranges are usually sold at Tk. 216 per dozen, How much extra/ less did she pay?

A Tk. 24 extra

B Tk. 10 extra

C Tk. 10 less

D Tk. 24 less

Correct Answer: Option B

real selling price of 1 orange is = 216/12=18 tk price of 5 oranges= 5x18=90 tk mini paid for 5 oranges=100 tk so,she paid = (100-90)tk =10 tk extra