Practice MCQ Questions and Answer on Time and Work

61.

If m men can do a work in r days, then the number of days taken by (m + n) men to do it is :

(A) $\frac{m + n}{mn}$
(B) $\frac{m + n}{mr}$
(C) $\frac{mr}{m + n}$
(D) $\frac{r (m + n)}{mn}$

Solution: M1 × D1 = M2 × D2 mr = (m +n) × D2 D2 = $\frac{mr}{m + n}$

62.

A alone can do $\frac{2}{5}$ of a work in 12 days. B is 25 percent more efficient than A. C alone can do the same work in 12 days less than B. D is 25 percent less efficient than C. If they all work together, then the work will be completed in how many days?

(A) $\frac{300}{47}$
(B) $\frac{240}{53}$
(C) $\frac{180}{43}$
(D) $\frac{200}{51}$

63.

A can do a piece of work in 6 days. B is 25% more efficient than A. How long would B alone take to finish this work ?

(A) $4 \frac{4}{5} days$
(B) $3 \frac{1}{3} days$
(C) $5 \frac{1}{4} days$
(D) $2 \frac{2}{3} days$

Solution: A : B Efficiency → 100% : 125% 4 : 5 Time 5 : 4 ×1.2↓ ↓×1.2 Actual time 6 days $4 \frac{4}{5}$ days

64.

A can finish a work in 18 days and B can do the same work in 15 days. B worked for 10 days and left the job. In how many days, A alone can finish the remaining work?

(A) 5
(B) $5 \frac{1}{2}$
(C) 6
(D) 8

Solution: $\begin{aligned} B's 10 day's work \\ = \frac{1}{15} \times 10 = \frac{2}{3} \\ Remaining work \\ = 1 - \frac{2}{3} = \frac{1}{3} \\ Now, \frac{1}{18} work is done by A in 1 day \\ ∴ \frac{1}{3} work is done by A in \\ 18 \times \frac{1}{3} = 6 days \end{aligned}$

65.

60 men could complete a piece of work in 250 days. They worked together for 200 days. After that work had to be stopped for 10 days due to bad weather. How many more men should be engaged to complete the work in time ?

(A) 10
(B) 15
(C) 18
(D) 20

66.

Kamal can do a work in 15 days. Bimal is 50% more efficient then Kamal. The number of days, Bimal will take to do the same piece of work, is = ?

(A) $7 \frac{1}{2}$
(B) 10
(C) 12
(D) 14

Solution: Ratio of times taken by Kamal and Bimal $\begin{aligned} = 150 : 100 \\ = 3 : 2 \end{aligned}$ Suppose Bimal takes x days to do the work $\begin{aligned} \Rightarrow 3 : 2 :: 15 : x \\ \Rightarrow x = (\frac{2 \times 15}{3}) \\ \Rightarrow x = 10 days . \end{aligned}$

67.

A's 2 days work is equal to B's 3 days work. If A can complete the work in 8 days, then to complete the work B will take ?

(A) 15 days
(B) 12 days
(C) 16 days
(D) 14 days

Solution: $\begin{aligned} According to the question, \\ \Rightarrow 2 A = 3B \\ \Rightarrow \frac{A}{B} = \frac{3}{2} \\ \Rightarrow Then efficiency ratio \\ A : B = 3 : 2 \end{aligned}$ ⇒ We know that time is inversely proportional to efficiency ⇒ Then time taken by them in ratio $\begin{aligned} A : B = \underset{8 days}{\underset{4 \times ↓}{2}} : \underset{12 days}{\underset{↓ \times 4}{3}} \\ ∵ A can do the work in 8 days \\ \Rightarrow i .e, 2 units \to 8 \\ 1 unit \to 4 \\ \Rightarrow Time taken by B \to 3 units \\ = 3 \times 4 \\ = 12 days \end{aligned}$

68.

X alone can complete a piece of work in 40 days. He worked for 8 days and left. Y alone completed the remaining work in 16 days. How long would X and Y together take to complete the work ?

(A) $13 \frac{1}{3} days$
(B) $14 days$
(C) $15 days$
(D) $16 \frac{2}{3} days$

Solution: Let total work = 40 units $\begin{aligned} X's 1 day work = 1 unit \\ X's 8 days work is \\ = 8 \times 1 \\ = 8 units \\ Work left = 40 - 8 = 32 \\ Y's 1 day work = 2 unit \\ X's 8 days work is = 1 units \end{aligned}$ X + Y complete the whole work together in $\begin{aligned} = \frac{40}{2 + 1} \\ = 13 \frac{1}{3} days \end{aligned}$

69.

A and B can do a job in 10 days and 5 days respectively. They worked together for two days, after which B was replaced by C and the work was finished in the next three days. How long will C alone take to finish 40% of the job?

(A) 15 days
(B) 18 days
(C) 10 days
(D) 12 days

Solution: Two days work of A and B = 3 × 2 = 6 Remaining work = 10 - 6 = 4 Now as per question $\begin{aligned} \frac{4}{1 + C} = 3 \\ \frac{4}{3} = 1 + C \\ C = \frac{1}{3} \end{aligned}$ So that 40% of total work done by $C = \frac{10 \times 40 %}{\frac{1}{3}} = 12$

70.

A can do a piece of work in 20 days and B in 15 days. With help of C, they finish the work in 5 days. In how many days C alone can do the same work ?

(A) 5 days
(B) 6 days
(C) 10 days
(D) 12 days

Solution: L.C.M. of Total Work =60 One day work of A = $\frac{60}{20}$ = 3 unit/day One day work of B = $\frac{60}{15}$ = 4 unit/day One day work of A + B + C = $\frac{60}{5}$ = 12 unit/day $\begin{aligned} C's efficiency \\ = 12 - 3 - 4 \\ = 5 \\ C will complete total work in \\ = \frac{60}{5} \\ = 12 days \end{aligned}$

«
1
2
3
4
5
6
7
8
9
10
...
35
36
Next ›
Last »

Indian Polity Mcq IAS GK Question India GK World GK GK questions GK Quiz Biology GK Science GK Physics GK Chemistry GK General Awareness Computer GK Political GK Indian Political GK Economics GK History GK Sports GK Geography GK Teaching Aptitude GK CTET/TET GK B Ed Entrance GK Banking GK SSC GK UPSC GK Indian Army GK Hindi Grammar GK Hindi Grammar MCQ Reasoning questions Bihar GK Rajasthan GK Jharkhand GK MP GK UP GK Chhattisgarh GK Haryana GK HP GK Maharashtra GK Electronics GK Agriculture GK States/Capitals GK Books Name & Author Arthimetic Verbal Reasoning Non Verbal Reasoning English

Practice MCQ Questions and Answer on Time and Work

General Knowledge