30)
a)
We have to calculate the highest common factor (HCF) of 21 and 36.
21=3*7
36=2² * 3²
HCF (21,36)=3.
Therefore: the length of the side of the largest pieces into which Juanita and Samuel can cut the pizza must be 3 inches.
Answer:3 inches.
b)
Area (pizza)=21 in * 36 in=756 in²
Area (0ne piece of pizza)=3 in * 3 in=9 in².
number of pieces of pizza=Area pizza / area of one piece of pizza.
number of pieces of pizzas=756 in²/ 9 (in²/piece)=84 pieces.
answer=84 pieces.
31)
x=number
-x=opposite of number "x"
The opposite of a number sometimes will be greater than the number itself.
if we have a negative number, the opposite of this number will be greater than the negative number.
Example:
x=-10
the opposite of -10 is 10
therefore: 10>-10
If we have a positive number, the opposite of this number will not be greater than the positive number.
Example:
x=10
the opposite of 10 is -10
Therefore: -10<10
Answer: 31.25%
Two ways to solve this problem:
#1: Use the formula: 
#2 Use a graphing calculator and use the function binompdf(n, p, x)
#1: Formula:

#2: Faster method
binompdf(6, 0.5, 3) = 0.3125
Answer:
50%
Step-by-step explanation:
He sold it for Rs 15 each. What is his profit percent? CP of 1 pen = 120/12= 10 SP of 1 pen = 15 Profit = 5 P % = (p/CP)*100=(5/10) x 100 = 50%.
Answer:
This is a linear graph.
Step-by-step explanation:
Since the x values increase at a constant of 1. The y-values have a 1st difference of -4 which means the graph is linear.
It would take 7:30 minutes to clear the rest of the 10 miles.