Algebra Word Problem Help?

OK. Let the time they work on it together be t. Then in that time, Mandy does t/4 of the work, and Cynthia does t/7. Together they do the entire job, so the equation is:

t/4 + t/7 = 1.

Get the left side to have the same common denominator (28); when you do the math, you end up with:

7t/28 + 4t/28 = 1

Now add the left side:

11t/28 = 1

Multiply through:

11t = 28

and divide:

t = 28/11

so the answer is 2 and 6/11 hours.

It takes mandy 4 hours to proof a chapter of homework and it takes cynthia 7 hours. Working together they will take only 4*7 / (4 + 7) hrs = 2 6/11 hrs ANSWER

mandy proofs at a rate of 1/4 of a chapter per hour, cynthia at 1/7 of a chapter per hour.

working together they do a rate of (1/4 + 1/7) or 11/28 of a chapter per hour.

therefore it would take them 28/11 pf an hour to complete it, or 152.7 minutes.

Rate problems can be exasperating . . .

Mandy's rate is one chapter per 4 hrs or 1/4 c/hr

Cynthia's rate is one chapter per 7 hrs or 1/7 c/hr

The equation is 1/4 (t) + 1/7 t = 1 chapter . . .

or t(1/4 + 1/7) = 1

t = 1/(1/4 + 1/7) = 2.54 hrs

t = time it takes them to proof the chapter together

t/4 + t/7 = 1

7t/28 + 4t/28 = 1

(7t+4t)/28 = 1

11t/28 = 1

11t = 28

t = 2.54 hours

Product divided by the Sum

4*7 / (4+7)

28 / 11

2 6/11 hours.........ANSWERS

The mathematical method is....

TimeTogether..........TimeTogether

-------------------...+...--------------------- = 1 job

TimeOfMandy.........TimeOfCynthia

T.......T

--..+..--..=..1...............Multiply every term by 28

4.......7

7T + 4T = 28

11T = 28

T = 28/11

T = 2 6/11 hours....ANSWER

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If the scholars modern-day grade is a ninety% then we’re needless to say assuming it’s out of one hundred% ninety/one hundred Now with the aid of fact the scholars grade more desirable 20% from the final grading era then you incredibly upload that to the previous one hundred% providing you with ninety/ a hundred and twenty = .75 and because grades are in probabilities you multiply .75 by utilising one hundred providing you with 75% with the aid of fact the scholars previous grade