How many ways can eight girls sit together in a row?

In 10080 ways

Step-by-step explanation:

We first treat the two people how have to sit together as 1 item taking up 2 seats so they have 7 possibilities of seats i.e. 12 23 34 45 56 67 78 and the two of them can sit in 2 possible ways, AB or BA

Now, the other 6 people will have 6 seats to choose from. So the total number of ways they can sit is 6 for the first person 5 for the second and so on so its 6!

Thus, the total number is = 10 080

19.side- angle- side

20. angle- side- angle

step-by-step explanation:

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.