Jill had a total score of 40 on 13 quizzes, so her average was
40/13 ≈ 3.08
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1 quiz @ 1 = total of 1
3 quizzes @ 2 = total of 6
4 quizzes @ 3 = total of 12
4 quizzes @ 4 = total of 16
1 quiz @ 5 = total of 5
total score = 1 + 6 + 12 + 16 + 5 = 40
total quizzes = 1 + 3 + 4 + 4 + 1 = 13
Step-by-step explanation:

Answer:
The possible values of x are 90°, 30° and 150°.
Step-by-step explanation:
Given that,
sin(2x) = cos(x) where 0° ≤ x < 180°
We know that, sin(2x) = 2 sinx cosx
2 sinx cosx = cosx
Subtract cosx on both sides
2 sinx cosx - cosx = 0
cosx (2sinx-1)=0
It means, cosx = 0 and (2sin x -1 ) = 0
cos x = cos0 and sinx = 1/2
x = 90° and x = 30°, 150°
Hence, the possible values of x are 90°, 30° and 150°.