Step-by-step explanation:
Let "c" be the original number of classrooms.
The 1200/c was the original number of students per classroom.
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Equation:
1200/(c-4) = (1200/c)+10
Multiply thru by c(c-4)
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1200c = 1200(c-4)+10c(c-4)
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1200c = 1200c-4800 + 10c^2-40c
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10c^2-40c-4800 = 0
c^2-4c-480 = 0
Factor:
(c-24)(c+20) = 0
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Positive solution:
c = 24 (# of classrooms originaly planned)
Answer:
0.072 or .072
Step-by-step explanation:
0.72 is ten times as much as 0.072.
0.072 times 10 is .72.
0.72 / 10 = 0.072 .
Answer:
Step-by-step explanation:
p(headache) = 0.45
p(headache | taking a vitamin) = 0.15/0.50 = 0.30
The two probabilities <em>are not equal</em>.
Answer:
Step-by-step explanation:
Let y represent students in the class
55% of y = 78
0.55y= 78
y = 142
h=20w
in one week hector works 20 hours
in two hector works 40 etc
h = hours and w = weeks. the money is just extra information.
h=20w works because if it has been two weeks we substitute the w with the number 2 and can solve
h=20(2)
h=20x2
h=40
This proves that the equation is true