Given:
The side of a square a, s+3.
The perimeter of a square is the sum of the four sides of the square. Hence,

16 students is the correct answer...
for every 5 boys there are 3 girls, so 20 boys 6 girls = the total of 16 students
Since we know that 1/4 is equal to 25%, or 0.25 in decimal form, we are able to work with 0.75 in the expression.
We are told to use j as the original price of the jeans, so we can set up the expression:

to represent the cost of the jeans with the discount.
Then to simplify, we simply take out j as a common factor, and solve what's in the parentheses:

or 
Using this equation, we can solve for the b part of the question. If the pair of jeans originally costs $60, plug in 60 to where j is in the expression:


Therefore, the cost of the jeans after the discount is C) $45.
The distance between the points (d) is found using the Pythagorean theorem.
Imagine the two points as defining the hypotenuse of a right triangle. The lengths of the legs of the triangle are the horizontal distance between the points and the vertical distance between the points. The the theorem tells us
d² = 4² + 7²
d² = 16 + 49
d² = 65
d = √65 ≈ 8.1
The distance between the points is
C 8.1_____
You know that the distance must be longer than the longest leg (7) and must be shorter than the sum of the two legs (4+7=11). The only answer choice between 7 and 11 is 8.1.