## dg2 one year ago A classroom has 26 rows (From A to Z), each row is divided in three columns and each column has five seats. To enter in the class, four doors (D1, D2, D3 and D4) are available and reaching up to the door two stairs (LH & RH) are available. A student wants to take the seat in the row C, F or P and then in how many ways he can get the seat.

1. OpenSessame

There are four doors and and two stair cases to each door, correct?

2. OpenSessame

You would use a permutation equation to solve this if I am reading this question correctly.

3. dg2

yes how to do, 26*15=390 c=15 ,p=15,f=15 so 45/390

4. OpenSessame

5. OpenSessame

First you must choose which stair case, there are 8. Then which door, 4 and so on.

6. OpenSessame

|dw:1389783816216:dw| Remember this too

7. dg2

how staircase only two

8. OpenSessame

i thought it was 2 stairs for every door sorry!

9. dg2

k tell me how to do

10. dg2

2 staircase,4 doors,15 seats for each row

11. dg2

15c1/390

12. dg2

15c1*4c1*2c1=120

13. dumbcow

yes however there are 3 rows (C,F,P) possible which means there are 45 seats to choose from --> 45*4*2 = 360

14. dg2

whether it is correct r not how to check