Working together, jenny and natalie can mop a warehouse in 5.14 hours. Had she done it alone it would have taken natalie 12 hour
2 answers:
Answer:
8.99 hours
Step-by-step explanation:
Let represent the time needed for Jenny to do the job alone.
Let represent the proportion of time needed for Natalie to do the job alone.
Similarly, let represent the proportion of time needed for Jenny to do the job alone.
Therefore:
First, set the common denominator to :
Then, multiply both sides by :
Next, subtract from both sides:
Now, divide both sides by :
Therefore, it would take Jenny about 8.99 hours to do the job alone.
You might be interested in
All three series converge, so the answer is D.
The common ratios for each sequence are (I) -1/9, (II) -1/10, and (III) -1/3.
Consider a geometric sequence with the first term <em>a</em> and common ratio |<em>r</em>| < 1. Then the <em>n</em>-th partial sum (the sum of the first <em>n</em> terms) of the sequence is
Multiply both sides by <em>r</em> :
Subtract the latter sum from the first, which eliminates all but the first and last terms:
Solve for :
Then as gets arbitrarily large, the term will converge to 0, leaving us with
So the given series converge to
(I) -243/(1 + 1/9) = -2187/10
(II) -1.1/(1 + 1/10) = -1
(III) 27/(1 + 1/3) = 18