The student would have to score 100% on their next test to brung their average up to 90. Here is why;
90+84+86=260
(260+?)/4=90
(260+100)/4=90
360/4=90
This is done to get the mean (or average) of a group of numbers by adding all the numbers and dividing by the amount of numbers you added together. Here it is divided by 4 because of the three tests he has taken and the test he will take.
The answer is 280,000 rounded to the nearest ten thousand.
Answer: it is 2 1/3
Step-by-step explanation:
-6e+2=-10
-10 -2=-12
-6e=-12
-12/-6
E=2
We need to build a system of equations:
a + b + c = 127......(1)
b - c = 13..............(2)
a - b - c = 41..........(3)
adding equations (1) and (3):-
2a = 168
a = 84
Substituting for in equation (1)-
84 + b + c = 127
b + c = 43...........(4)
Adding equations (2) and (4):-
2b = 56
b = 28
Finally from equation (2)
c = 28-13 = 15
Answer is Country a had 84 points , b had 28 points and c had 15 points.