New SAT Counting Problems

 

             

   

01- To buy a computer system, a customer can choose one of 4 monitors, one of 2 keyboards, one of 4 computers and one of 3 printers. Determine the number of possible systems that a customer can choose from.

4 * 2 * 4* 3 = 96

02- A man has 3 different suits, 4 different shirts and 5 different pairs of shoes. In how many different ways can this man wear a suit, a shirt and a pair of shoes?

3 * 4 * 5  = 60

03- A teacher has prepared 20 arithmetic’s tasks and 30 geometry tasks. For a test he‘d like to use: 

 3 arithmetic’s and 2 geometry tasks

²⁰P₃ * ³⁰ P ₂

04- How many different ways can we arrange the letters BBBACDE?

Answer 7!/ 3! = (7)(6)(5)(4) = 840