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Quantitative Aptitude

TIME AND WORK MCQs

Time & Work, Work And Wages

Total Questions : 1512 | Page 7 of 152 pages
Question 61.

A and B can do a work in 8 days, B and C can do the same work in 12 days. A, B and C together can finish it in 6 days. A and C together will do it in :

  1.    4 days
  2.    6 days
  3.    8 days
  4.    12 days
 Discuss Question
Answer: Option C. -> 8 days

(A + B + C)'s 1 day's work = \(\frac{1}{6}\)


(A + B)'s 1 day's work = \(\frac{1}{8}\)


(B + C)'s 1 day's work = \(\frac{1}{12}\)


So , (A + C)'s 1 day's work  = \(\left(2\times \frac{1}{6}\right)-\left(\frac{1}{8}+\frac{1}{12}\right)\)


= \(\left(\frac{1}{3}-\frac{5}{24}\right)\)


= \(\frac{3}{24}\)


= \(\frac{1}{8}\)


So, A and C together will do the work in 8 days.

Question 62.

A can finish a work in 24 days, B in 9 days and C in 12 days. B and C start the work but are forced to leave after 3 days. The remaining work was done by A in:

  1.    5 days
  2.    6 days
  3.    10 days
  4.    \(10\frac{1}{2}days\)
 Discuss Question
Answer: Option C. -> 10 days

(B + C)'s 1 day's work = \(\left(\frac{1}{9}+\frac{1}{12}\right)=\frac{7}{36} \)


Work done by B and C in 3 days = \(\left(\frac{7}{36}\times3\right)=\frac{7}{12} \)


Remaining work =  \(\left(1-\frac{7}{12}\right)= \frac{5}{12}\)


Now,   \(\frac{1}{24} \)    work is done by A in 1 day.


So,  \(\frac{5}{12}\)   work is done by A in \(\left(24\times\frac{5}{12}\right)= 10 days.\)

Question 63.

X can do a piece of work in 40 days. He works at it for 8 days and then Y finished it in 16 days. How long will they together take to complete the work?

  1.    \(13\frac{1}{3}days\)
  2.    15 days
  3.    20 days
  4.    26 days
 Discuss Question
Answer: Option A. -> \(13\frac{1}{3}days\)

Work done by X in 8 days = \(\left(\frac{1}{40}\times8\right)=\frac{1}{5}\)


Remaining work = \(\left(1-\frac{1}{5}\right)=\frac{4}{5}\)


Now,   \(\frac{4}{5}\)  work is done by Y in 16 days.


Whole work will be done by Y in \(\left(16\times\frac{5}{4}\right)= 20 days.\)


So, X's 1 day's work =  \(\frac{1}{40}\) , Y's 1 day's work = \(\frac{1}{20}\)  


(X + Y)'s 1 day's work = \(\left(\frac{1}{40}+\frac{1}{20}\right) = \frac{3}{40}\)


Hence, X and Y will together complete the work in \(\left(\frac{40}{3}\right) = 13\frac{1}{3}days.\)

Question 64.

A and B can do a job together in 7 days. A is \(1^{\frac{3}{4}}\)  times as efficient as B. The same job can be done by A alone in :

  1.    \(9\frac{1}{3}\)
  2.    11 days
  3.    \( 12\frac{1}{4}\)
  4.    \(16\frac{1}{3}\)
 Discuss Question
Answer: Option B. -> 11 days

(A's 1 day's work) : (B's 1 day's work) = \(\frac{7}{4}:1 = 7:4\)


Let A's and B's 1 day's work be 7x and 4x respectively.


Then, 7x + 4x =   \(\frac{1}{7}\Rightarrow 11x =\frac{1}{7}\Rightarrow x=\frac{1}{77}\)


So, A's 1 day's work =   \(\left(\frac{1}{77}\times7\right) = \frac{1}{11}\)

Question 65.

A and B together can do a piece of work in 30 days. A having worked for 16 days, B finishes the remaining work alone in 44 days. In how many days shall B finish the whole work alone?

  1.    30 days
  2.    40 days
  3.    60 days
  4.    70 days
 Discuss Question
Answer: Option C. -> 60 days

Let A's 1 day's work = x and B's 1 day's work = y.


Then , x+y =   \(\frac{1}{30}\)   and 16x + 44y = 1.


lving these two equations, we get: x =    \(\frac{1}{60}\) and y =  \(\frac{1}{60}\)


Therefore , B's 1 day's work = \(\frac{1}{60}\)


Hence, B alone shall finish the whole work in 60 days.

Question 66.
  1. 5 men are equal to as many women as are equal to 8 boys. All of them together earn Rs 90 daily. A man’s wage is

  1.    Rs 4 
  2.    Rs 5
  3.    Rs 6
  4.    Rs 7
 Discuss Question
Answer: Option C. -> Rs 6
Let the daily wage of a man, a woman, and a boy be m, w, and b, respectively.
From the given statement, we can form the following equations:
5m = w (because 5 men are equal to as many women)w = 8b (because as many women are equal to 8 boys)
Substituting the second equation in the first, we get:
5m = 8b
Or, m = (8/5)b
Now, we can write the total daily wage as:
5m + w + 8b = 90
Substituting the value of w from the second equation, we get:
5m + 8b + 8b = 90
Or, 5m + 16b = 90
Substituting the value of m from the earlier equation, we get:
5(8/5)b + 16b = 90
Or, 8b + 16b = 90
Or, 24b = 90
Or, b = 90/24 = 15/4
Substituting the value of b in the equation for m, we get:
m = (8/5) x (15/4) = 6
Therefore, the daily wage of a man is Rs 6, which is option (C).
Question 67.

  1. X and Y undertook a piece of construction work for Rs 4500. X alone could do it in 8 days and Y in 12 days. Find their share in the money.

  1.    Rs 1800, Rs 2400
  2.    Rs 2400, Rs 1800
  3.    Rs 2700, Rs 1800
  4.    Rs 1800, Rs 2700
 Discuss Question
Answer: Option C. -> Rs 2700, Rs 1800
Question 68.

  1. If 3 men and 4 girls earn Rs 750 in 3 days and 10 men and 18 girls earn Rs 4750 in 5 days, in what time will 14 men and 10 girls earn Rs 15200?

  1.    12 Day
  2.    16 day
  3.    18 days
  4.    20 days
 Discuss Question
Answer: Option B. -> 16 day
Question 69.

  1. A can do a piece of work in 10 days while B alone can do it in 15 days. They work together for 5 days and the rest of the work is done by C in 2 days. If they get Rs 450 for the whole work, how should they divide the money?

  1.    Rs 100 , Rs 150 , Rs 200
  2.    Rs 200 , Rs 150 , Rs 100
  3.    Rs 255 , Rs 150 , Rs 75
  4.    Rs 150 , Rs 225 , Rs 75
 Discuss Question
Answer: Option C. -> Rs 255 , Rs 150 , Rs 75
Question 70.
  1. I engaged a man for a certain number of days for Rs 1725. He was absent for 7 days. I paid him Rs 920. What was his daily wage?

  1.    Rs 95
  2.    Rs 115
  3.    Rs 125
  4.    Rs 135
 Discuss Question
Answer: Option B. -> Rs 115

Let's assume the daily wage of the worker to be x.
Total wage for n days = n*x
Given, the worker is engaged for a certain number of days for Rs 1725, therefore we have:
n*x = 1725 ...(1)
Now, the worker was absent for 7 days, so the total number of days worked would be (n-7).
Given, the worker was paid Rs 920, so we have:
(n-7)*x = 920 ...(2)
On solving equations (1) and (2), we get:
n = 23 and x = 75
Therefore, the daily wage of the worker is Rs 75.

Explanation:
Let's assume the daily wage of the worker to be x.
The total wage paid for n days is given as Rs 1725. Therefore, we get the equation:
n*x = 1725
The worker was absent for 7 days. Therefore, the total number of days worked by the worker is (n-7). The amount paid to the worker is given as Rs 920. Therefore, we get the equation:
(n-7)*x = 920
On solving the above two equations, we get:
n = 23 and x = 75
Therefore, the daily wage of the worker is Rs 75.
Some relevant definitions and formulas used in the solution are:
Linear equation: An equation of the form "ax + b = c", where "a", "b", and "c" are constants and "x" is a variable.
System of linear equations: Two or more linear equations with the same variables.
Substitution method: A method for solving a system of linear equations by solving one equation for one variable and substituting the result into the other equation(s).
Variable: A symbol or letter used to represent an unknown quantity in an equation or expression.


If you think the solution is wrong then please provide your own solution below in the comments section .

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