Answer:
The first answer, 3 times the square root of x squared is correct.
The most accurate way would be the fourth answer, because to estimate 66% of 47 you need to round both as closely as possible. 66% rounds closest to 2/3, and 47 is closest to 48
Answer:
and 
Step-by-step explanation:
Options

Required
Select the unit rates
Unit rate involve two items where the first item being measured can be any positive number, but the second item must be measured in units (i.e. 1)
For clarity:
If
represents unit rate, then 
Having said that:
Only
and
satisfy the condition of unit rates; others are not because they have a denominator other than 1
Answer:
So we know the total is 34
B to C will be 15 so that's around half the total
So let's subtract the given part from the total
34 = 15 = 19
AB = 19