Answer:
C) 15
Step-by-step explanation:
Here we have to use the combination to find the number of possible combinations.
Total number of classmates (n) = 6
We are selecting 2 individuals. So r = 2.
The combination formula nCr = 
Plug in n = 6 and r =2, in the above formula, we get
= 
= 
Simplifying the above factorial, we get
= 15
So the answer is C) 15
S= 15
3s=45
3s/3=45/3
S=15
You have to divide both sides
The factor pairs of a number when multiplied give the original number.
Therefore, all the factor pairs of 28 are:

The correct choice is the first one
Answer: 12pm
Step-by-step explanation: it takes him 2 hours to fill 1800 another 2 hours would be 12pm if you have 1000+1000 you get 2000. then add 800 and 800. you get 1600 add them all together you get 3600.
40 percent 3/5 equals 60, 5/5 equals 100, 100-60 equals 40 percent