Let's begin by listing out the information given to us:
There are four students: n = 4
Number of students to be selected: r = 2
To calculate the combination of 2 students to be chosen, we use:

Therefore, there 12 possible combinations from these
The answer is ten plz thank
You have to show us the image Sherlock
Answer:
all answers below
Step-by-step explanation:
(i) 2704 = 2^4 x 13^2
(ii) as both indices (the powers) are divisible by 2, it is a perfect square.
(iii) as both indices are not divisible by 3, it is not a perfect square.
In five quarts, we have 2 quarts of acid and 3 quarts of water
total = (2 + 3) = 5 quarts
concentration = 2 / 5
We want a 30% concentration
total volume = 2 + x
.30 = 2 / (2+x)
.6 + .30 x = 2
.30x = 1.4
x = 4.66666 gallons of water
(or we need to add 1.666666 gallons of water)
Double Check:
acid concentration = 2 / (2 + 4.666666)
acid concentration = .30