Find total instruments:
20+20+45+15 = 100
20 are brass
The portion would be number of brass over total:
20/100 which reduces to 1/5 are brass
Answer: 271
Step-by-step explanation:

Answer:
b>44
Step-by-step explanation:
12/5<b-8/15
switch sides b-8/15>12/5
multiply both sides by 15 15(b-8)/15>12*15/5
simplify b-8>36
add 8 to both sides b-8+8>36+8
simplify
b>44
Answer:
34 and 30
Step-by-step explanation:
8 times 3 = 34
and 34-4=30
divide 8 by 2 and you'll get 4
so, 34-4=30
Answer:
6/5 miles per hour or 1.2 miles per hour
Step-by-step explanation:
If Natalie walked 3/5 miles in 1/2 hour, then in 1 hour she would have walker 6/5 miles(3/5 * 2). You can write 6/5 as 1.2 (6 divided by 5). Thus, Natalie walked 1.2 miles per hour