Answer:

Step-by-step explanation:
Look at the image below ↓
First case:
average of test score =70
number of students =p
total score of 'p' students = ( average of test score)*( number of students)
total score of 'p' students =70p
Second case:
average of test score =92
number of students =n
total score of 'n' students = ( average of test score)*( number of students)
total score of 'n' students =92n
total number of students = p+n
total average score =86
so, total score =86(p+n)
total score = total score of 'p' students +total score of 'n' students

now, we can simplify it



now, we can find p/n

................Answer
Answer: The mean is 50.42. The Median is 40. The mode is 95
Step-by-step explanation:
Answer:
Step-by-step explanation: d - angle c is congruent to z
because the angles that are oppostie are equal to each other.
Pls let me know if its correct.
Answer: the old price for 1 liter is $0.3
Step-by-step explanation:
Let x represent the old price for 1 liter of petrol.
Last week a man bought 20 liters at the old price. This means that the total amount that the man paid for 20 liters is 20x.
The cost of petrol rises by 2 cents a liter. This means that the new price per liter is x + 2/100 = x + 0.02
This week he bought 10 liters at the new price. This means that the total amount that the man paid for 10 liters is
10(x + 0.02)
= 10x + 0.2
Altogether, the petrol costs $9.20. This means that
20x + 10x + 0.2 = 9.2
30x + 0.2 = 9.2
30x = 9.2 - 0.2
30x = 9
x = 9/30
x = 0.3