Answer: 
Step-by-step explanation:
For this exercise it is important to remember the following:

Given the following expression:

You can notice that the radicand (the number inside the square root) is negative. Therefore, in order to simplify the expression, you need to follow these steps:
1. Replace
with
and simplify:

2. Descompose 12 into its prime factors:

3. Substitute into the expression:

4. Since
, you can simplify it:

Use some bricks and paint. paint the bricks
Answer is 280
First, find A = 35% (100% less the three known percents = 35
Second, find ratio of B
20% of x = 160
Divide 160/.20 to isolate x
X=800 (total biscuits)
Now take A percentage x 800 biscuits
800 x 35% = 280 people chose biscuit A
Answer:
If he includes himself then:
Split up the cookies into 4 equal parts.

3.75 cookies each if he includes himself.
If he does not include himself:
Split up the cookies into 3 equal parts

5 cookies each if he shares to his friends without including himself.