81 degrees
1 degree = 2 pi / 360
81 degrees = 162 pi / 360
=9 pi / 20
L (arc) = radius x angle
= 10 x 9 pi / 20
90 pi /20
9/2 pi : D
The answer is D
Answer:
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Step-by-step explanation:
Answer:
30
Step-by-step explanation:
Work backwards:
- 6 is 3/5 of a number, and that number is 10
- 10 is 1/3 of a number, and that number is 30
Check your work:
- 2/3 of 30=20 toy to Sarah
- 30-20=10 toys left
- 2/5 of 10=4 toys to Ryan
- 10-4=6 toys left
Answer:
dont know sry
Step-by-step explanation:
18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.
<u>Step-by-step explanation:</u>
Let x = kg of 15% copper alloy
Let y = kg of 60% copper alloy
Since we need to create 90 kg of alloy we know:
x + y = 90
51% of 90 kg = 45.9 kg of copper
So we're interested in creating 45.9 kg of copper
We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:
0.15x + 0.60y = 45.9
but
x + y = 90
x= 90 - y
substituting that value in for x
0.15(90 - y) + 0.60y = 45.9
13.5 - 0.15y + 0.60y = 45.9
0.45y = 32.4
y = 72
Substituting this y value to solve for x gives:
x + y = 90
x= 90-72
x=18
Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.
