Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
The are parallel to each other because the are both straight horizontal lines
Answer:
wala kang jowa..........................
Answer:
A. Cylinder + cone
<u>Volume is the sum of volumes:</u>
- V = Vcon + Vcyl = 1/3πr²h₁ + πr²h₂
- V = 1/3π*9²*12 + π*9²*120 = 31554.2 cm³
<u>Surface area of cone:</u>
- A = A=πr(r+√(h₁²+r²)) = π*9(9 + √(9²+12²)) = 678.6 cm²
<u>Surface area of cylinder minus bases:</u>
- A = 2πrh₂ = 2π*9*120 = 6785.8 cm²
<u>Total surface area:</u>
- 678.6 + 6785.8 = 7464.4 cm²
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B. Cube+ pyramid
<u>Volume:</u>
- V = a³ + (1/3)a²h = a³ + (1/3)a²√(l²-(a/2)²)
- V = 8³ + (1/3)8²√(10²-4²) = 707.5 cm³
<u>Surface area of pyramid:</u>
- A = a² + 2al = 8² + 2*8*10 = 224 cm²
<u>Surface area of cube minus bases:</u>
- A = 4a² = 4(8²) = 256 cm²
<u>Total surface area:</u>
