Computers manufactured by a certain company have a serial number consisting of three letters of the alphabet followed by a three-digit number. If all the serial numbers of this type have been used(repetition is not allowed), how many sets have already been Three boys and six girls are being seated in a row of nine chairs on a stage which are numbered from left to right. How many seating arrangements are there if

Here's the complete question for question 2.

Three boys and six girls are being seated in a row of nine chairs on a stage which are numbered from left to right. How many seating arrangements are there if Girls sit in the first two seats as well as the last seat?

these are two different questions. the answers are below.

1. 11,232,000

2. 86400

Step-by-step explanation:

1.

We have 26 letters in the alphabets from a-z

Now this question tells us that there is no repetition. So when first letter is chosen from 26, we are left with 25 alphabets, if another 1 is taken from 25 we have 24 left.

We can choose 3 alphabets in 26x25x24 ways

We have 10 numbers from 0-9

When we take 1 number away from this 10 we have 9 left, another 1 from remaining 9 leaves us with 8

= 10x9x8

Total number of manufactured sets =

26x25x24x10x9x8

= 11,232,000

2.

For girls, g2, g2, g3, g4, g5, g6.

For boys, b1,b2,b3

Girls take the first two seats and the last seat

We can fill 3 places in 6P3 ways = 120

We have 6 seats left which can be filled in 6! Ways = 720

120x720 = 86400 ways

1. is 4 and 2. is 3

step-by-step explanation:

so if you look at the first one you see that 1 is to 4 and 2 is to 8 and so on, so you can see for every 1 there is a times 4 so if it were 3 then it would be 3*4 and it is 12

for number 2 it is 3 because 1 is to 3 and 2 is to 6 so for every 1 there is 3 so if it were 3 then there would be 3*3 = 9

in 4 days he will run   12/14

step-by-step explanation: