First, you add up the total number of students because we would base our percentage one this.
Total number of students = 1+4+5+10+20+10+5
Total number of students = 55
Now, let's count how many of them got a score of more than 70. For this, you would only count the students belonging to 70-under 80, 80-under 90 and 90-under 100.
Students who got more than 70 = 20+ 10 + 5 = 35
Therefore the percentage is equal to:
Percentage = 35/55 * 100 = 63.64%
Answer:
40% of the class is Girls, so 12 students are girls
Step-by-step explanation:
add up the ratio
2+3=5
divide by 5
30/5=6
multipy ratio to find totial number of students
2*6=12
2*3=18
divide the number of students to get the pecentage
12/30=0.4=40%
18/30=0.6=60%
Answer:
2.45 × 
Step-by-step explanation:
using the rules of exponents
•
= 
•
= 
evaluating the numerator
(3.8 ×
)² = 3.8² ×
= 14.44 × 
R = 
=
× 
= 2.45 ×
← to 2 dec. places
Answer:
The numbers are 18 and 91
Step-by-step explanation:
You can translate the information to two equations:
<em>a value 5 times a smaller number is 1 less than a larger number</em>
5a = b - 1
<em>their difference is 73</em>
b - a = 73
Then you should merge one equation into the other, thereby eliminating one variable. You can do this any way you want. I choose to rewrite the first equation as:
b = 5a + 1
Now I can write 5a+1 in the second equation at the place where b was:
5a + 1 - a = 73
It is now an equation with only one variable, solve by simplifying
4a = 72
a = 18
Now b can be found using b = 5a + 1
b = 91