Answer:
D
Step-by-step explanation:
Firstly, since it is a selection question, we shall be using a combination approach.
So here we are trying to select the best answer that describes that 2 out of 10 students are selected.
Let’s consider the scenario below;
selecting r out of n can be resolved using the combination nCr
= n!/(n-r)!r!
Now in this case, our n = 10 and r = 2.
Thus, 10C2, we have ;
10!/(10-2)!2! = 10!/8!2! = (10 * 9 * 8!)/8!2! = (10 *9)/2! = 90/2 = 45
Thus, 10C2 = 45
Here, the order of selection does not matter as we can select in random fashion. This makes option D correct
Answer:
Jenna needs 2 yards of ribbon to wrap 4 boxes.
Step-by-step explanation:
First, we can find how many inches of ribbon she needs.
18*4=72
She needs 72 inches of ribbon for 4 yards.
There are 36 inches in a yard.
72/36=2
Jenna needs 2 yards of ribbon to wrap 4 boxes.
If you have 50. and want to make it 5000 you can move the decimals point over 2 which would also be ×100
Answer:
Step-by-step explanation:
This book has 500 pages in total.
We should split up the place values.
1 - 9
One only appears once.
1
10 - 19
One appears 11 times.
1 + 11
20 - 99
One only appears 8 times.
1 + 11 + 8
Add:
1 + 11 + 8
=> 20
Since the same is for 200-299, and so on. Let us add twenty four times.
20 * 4
=> 80
Looking back to 100-199, there are 120 ones.
Add:
120 + 80
=> 200