ANSWER: 0.64 cents
EXPLANATION: 0.49x1.31 = 0.6419 = 0.64
17 books in total, and 8 new. To find the number of used books, we subtract 8 from 17.
17-8= 9 used books
Now we have 8 new books and 9 used books.
All books: 17
Used books: 9
New books: 8
(a) all books: used books
17: 9
(b) new books: used books
8: 9
The answer that is needed in the blank is disturbance
The length of the brace required is 4.3m
What is sine rule?
In a ΔABC a, b and c are the sides and A, B and C are angles then,

We can find the length, l as shown below:
Let AB=3m, BC=2m and AC=l
Let ∠A=25°
So, in ΔABC




∠C=39.34°
∠A+∠B+∠C=180°
∠B=180°-25°-39.34°
∠B=115.66°



l=4.2659
Rounding to nearest tenth of meter.
l=4.3m
Hence, the length of the brace required is 4.3m
Learn more about Sine Rule here:
brainly.com/question/25852087
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