Hi there!

Let there be two angles, ∠A and ∠B, that are supplementary to each other. Therefore:
∠A + ∠B = 180°
We can assign ∠B to be the greater angle. Assume ∠A has a measure of x°.
∠A = x°
∠B = x° + 30°
The sum is equal to 180°, so:
x° + (x° + 30°) = 180°
Solve for x°.
2x° + 30° = 180°
2x° = 150°
x° = 75°
Thus, ∠A = 75°.
Since ∠B is 30°, greater:
∠B = 75° + 30° = 105°.
Answer:
Step-by-step explanation:
To answer this question, first we need to figure out how much of the board Rafi cut off.
To do this, we need to multiply the length of each piece by the number of pieces he cut off.
3 7/8 = 3.875
3.875 * 3 = 11.625
Now, because we knew Rafi cut off 11.625 feet off of the board, we just need to subtract this length from the length of the entire board to find the remaining length.
15 1/2 = 15.5
15.5 - 11.625 = 3.875
There is 3.875 feet or 3 7/8 of the board left.
She would have to study about 48 hours to get a score of 97.
Hopefully that helped! :)