Answer:
Dan = 68
bobbi = 62
Step-by-step explanation:
Let Bobbi's height = b
Let Dan's height = d
the following equations can be determined from the question
b + d = 130 eqn 1
3b - d = 118 eqn 2
Multiply eqn 1 by 3
3b + 3d = 390 eqn 3
Substract eqn 2 from 3. this gives
4d = 272
d = 68
Substitute for d in eqn 1
b + 68 = 130
b = 62
<h3>
Answer:</h3>
6 hours
<h3>
Step-by-step explanation:</h3>
The two hoses together take 1/3 the time (4/12 = 1/3), so the two hoses together are equivalent to 3 of the first hose.
That is, the second hose is equivalent to 2 of the first hose. Two of the first hose could fill the vat in half the time one of them can, so 6 hours.
The second hose alone can fill the vat in 6 hours.
_____
The first hose's rate of doing work is ...
... (1 vat)/(12 hours) = (1/12) vat/hour
If h is the second hose's rate of doing work, then working together their rate is ...
... (1/12 vat/hour) + h = (1/4 vat/hour)
... h = (1/4 - 1/12) vat/hour = (3/12 -1/12) vat/hour = 2/12 vat/hour
... h = 1/6 vat/hour
so will take 6 hours to fill 1 vat.
Simple! 1/3 times 3 equals 3/3, or 1.
The class is weighted as follows:
60% Regular Tests
10% Final Exam
15% Project
15% Homework
The total weighted points possible for the class are as follows:
(100+100+100+100+100)*.6 + 100*.1 + 100*.15 + 100*.15 = 340
To calculate her individual final weighted grade we plug in her scores for each category and complete the following computation:
(92+83+77+84+82)*.6 + 88*.1 + 95*.15 + 77*.15 = 285.4
So her weighted grade percent would be 285.4/340 = 83.9% which is a B.
