Answer:
a. 47
b. 87
c. 127
Step-by-step explanation:
Assume a total of 4 exams ( first 3 plus a final)
Let final score be X,
Hence, average score = (85 + 71 + 77 + x) / 4 = (233 + x) / 4
a) to get a C, the average score must be 70
70 = (233 + x) / 4
(233 + x) = 70 (4) = 280
x = 280 - 233 = 47 (Ans)
b) to get a B, the average score must be 80
80 = (233 + x) / 4
(233 + x) = 80 (4) = 320
x = 320 - 233 = 87 (Ans)
c) to get a A, the average score must be 90
90 = (233 + x) / 4
(233 + x) = 90 (4) = 360
x = 360 - 233 = 127 (Ans)
(n-21)/2=4n is the equation
First, divide what is in the parentheses by 2
0.5n-10.5=4n
Then, multiply the whole equation by 2 so we have all whole numbers
n-21=8n
Move N so that it is with 8n
7n=-21
Divide 21 by 7
n=-3
Solution: The number (n) is equal to -3
Answer: 350% is your answer just 7/2×100= 350%
Step-by-step explanation:
