Let x be the number of 5 points question.
Let y be the number of 2 points question.
Total number of questions is 38
x + y = 38
Total points is 100
5x + 2y = 100
x + y = 38 ------------- (1)
5x + 2y = 100 ---------(2)
From (1):
x + y = 38
x = 38 - y -------------- sub into (2)
5(38 - y) + 2y = 100
190 - 5y + 2y = 100
3y = 90
y = 30 ------------------ sub into (1)
x + 30 = 38
x = 38 - 30
x = 8
There are 8 5-point questions and 30 2-point questions
A. The temperature goes higher-lower-steady/same-lower-same.
B. I do not understand the question
I = 8.
k = 4
j = sqrt(8^2 + 4^2) = 8.944.