Answer:
495 combinations of 4 students can be selected.
Step-by-step explanation:
The order of the students in the sample is not important. So we use the combinations formula to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

How many combination of random samples of 4 students can be selected?
4 from a set of 12. So

495 combinations of 4 students can be selected.
Answer:
.55 difference or 11/20
Step-by-step explanation: hope this helps
(Don't know what the number line looks like)
Convert both to decimals, then subtract
Answer:
D + 50 - 20 = 70
D = 70
Step-by-step explanation:
The statement that best describes the two expressions is
D. A is irrational, but B is rational
square root of 64 plus square root of 5 is 8 plus square root of 5, the square root of 5 is an irrational number which makes the entire expression an irrational number
square root of 64 plus square root of 4 is 8 plus 2 which is equal to 10 and is a rational number