you are going to a baseball game with your younger sibling.when you get there, you find an empty row with 30 seats. In order to save room for your friends you decide to save at least three empty seats between the two of you. givin the requirement how many differnt choics are there for where you and your sibling can sit in the row? explain anwsers please.
2007-05-17 19:19:51 · 4 answers · asked by Jay7 2 in Science & Mathematics ➔ Mathematics
You and your sibling have to save AT LEAST 3 empty seats
so we have to vary the no. of empty seats from 3 to 28
When no. of empty seats is exactly 3 you have to select 5
consecutive seats which can be done in 26 different ways
now two persons can occupy the extreme seats in 2! ways
so number of ways in this case = 26 * 2!
Similarily if no. of empty seats is 4,then no. of ways = 25*2!
If no. of empty seats is 5 then no. of ways = 24 * 2!
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If no. of empty seats is 28 then no. of ways = 1 * 2!
Total no. of such ways
= (26 + 25 + 24 + --------------+ 1) 2!
= 702
2007-05-17 20:07:17 · answer #1 · answered by bharat m 3 · 0⤊ 0⤋
This is a small enough problem that you can draw it. Take graph paper, choose a row of 30 spaces. Take a block of 5 spaces (you, your baby sister, and 3 spaces between you) and step it across the row.
2007-05-18 02:25:18 · answer #2 · answered by Charley M 3 · 1⤊ 0⤋
26
draw 30 spaces and fill in your positions thn count the no. of ways you can do it
2007-05-18 02:41:00 · answer #3 · answered by Maths Rocks 4 · 0⤊ 0⤋
25 cuz after that someone goes into the aisle.
2007-05-18 02:25:51 · answer #4 · answered by ignoramus 7 · 0⤊ 0⤋