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SR = 450
<span>S = 450/R </span>
<span>(S - 3)(R + 5) = 450 </span>
<span>(450/R - 3)(R + 5) = 450 </span>
<span>(450 - 3R)(R + 5) = 450R </span>
<span>450R + 2250 - 3R^2 - 15R = 450R </span>
<span>3R^2 + 15R - 2250 = 0 </span>
<span>R^2 + 5R - 750 = 0 </span>
<span>R^2 + 30R - 25R - 750 = 0 </span>
<span>R(R + 30) - 25(R + 30) = 0 </span>
<span>(R + 30)(R - 25) = 0 </span>
<span>R ∈ {-30,25}
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<span>Only positive numbers make sense in this context, therefore R = 25.</span>
The last option
I hope this is right let me know if its wrong and ill correct it
Calculate the volume of sand, the cone will be completely filled and the cylinder will have sand up to the 30 mm level.
Volume of sand will = the volume of the cone:
= 1/3 * pi * (6 mm)^2 * 15
= 1/3 * pi * 36 * 15 =180 pi cubic mm
the cylinder will have a volume of sand equal to:
= pi * (6 mm)^2 * 30 mm
= pi * 36 sq mm * 30 mm
= 1080 pi cubic mm
The total sand is the sum:
= 1080 pi cubic mm +180 pi cubic mm
= 1260 pi cubic mm.
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Answer: $14.0
Step-by-step explanation:
For us to calculate this question, we have to find 20% of $17.45 and then subtract the value gotten from $17.45. This will be:
= $17.45 - (20% × $17.45)
= $17.45 - (0.2 × $17.45)
= $17.45 - $3.49
= $13.96
= $14.0 to nearest cent
