a group of people ordered pencils. the bill was $1.87. if the original price of each was 12 cents and the price has risen, how much does each cost?

Question

 i want to know how much each pencil cost.

Answer 1

First, you should realize that 187=11*17.

 

Both 11 and 17 are prime numbers.  If the cost of a pencil is a whole number of cents, and if it is larger than 12 ("the price has risen"), then the price must be 17 cents each and the group bought 11 pencils.