Advertisements

Basic Math MCQ 12 (Work and days)

MCQ 12:  P and Q can complete a work in 15 days and 10 days respectively. They started the work together and then Q left after 2 days. P alone completed the remaining work. The work was finished in__________days.

a) 12               b) 15                  c) 22                d) 20

Solution:

Let the amount of wok = x

For P

work in 15 days = x

work in 1 day =x/15

Or we simply write

Wp = x/15

Similarly for Q

Wq= x/10

 

Worl done by both P & Q in one day together = x/15+x/10= 5x/30= x/6

or

simply

Wp+Wq = x/6

Work done in two days = ​\( 2\times \frac{x}{6} =\frac{x}{3} \)

 

Remaining work = ​\( x -\frac{x}{3}=\frac{2x}{3} \)

 

This remaining work is to be done by P alone !

We arrange data for P as under;



Work Days
x 15
2x/3 Z

 

Here it is direct proportion in work and days i-e more wok more days , so

\[ \frac{\frac{2x}{3}}{x}=\frac{z}{15} \]

\[ \frac{2}{3}=\frac{z}{15} \]

\[ z= \frac {2\times15}{3}=10 \]

So the remaining work will be done by P in 10 days

 

Total day in which work was done by P = work done with Q + work done as alone = 2+10 = 12 days !

So option  a is correct!

 

Digiprove sealCopyright secured by Digiprove © 2020
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  

You may submit a MCQ or maths problem with solution tips here in the comment box below! If you could not solve anyone, you may submit a MCQ or maths problem without solution as well. We will try our level best to solve it for you!

Your email address will not be published.

You may use these <abbr title="HyperText Markup Language">HTML</abbr> tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

All original content on these pages is fingerprinted and certified by Digiprove
Insert math as
Block
Inline
Additional settings
Formula color
Text color
#333333
Type math using LaTeX
Preview
\({}\)
Nothing to preview
Insert