retagged by
4,495 views
11 votes
11 votes

S, M, E and F are working in shifts in a team to finish a project. M works with twice the efficiency of others but for half as many days as E worked. S and M have $6$ hour shifts in a day, whereas E and F have $12$ hours shifts. What is the ratio of contribution of M to contribution of E in the project?

  1. $1:1$
  2. $1:2$
  3. $1:4$
  4. $2:1$
retagged by

6 Answers

Best answer
14 votes
14 votes
Let the efficiency of $S, E$ and $F$ be $r$ units/hour.
So the efficiency of $M = 2r$ units/hour.

Let the number of days $E$ works be $d$, so that of $M$ is $d/2$.

The amount of work done by $M,$ $W_{m} = 2r \times (d/2) \times 6.$
(As $M$ is working $6$ hours per day)

The amount of work done by $E,$ $W_{e} = r \times d \times 12.$

$W_{m}$ : $W_{e}$ = $\frac{2r \times (d/2) \times 6}{r \times d \times 12} = 1 : 2.$

Correct Answer: $B$
edited by
2 votes
2 votes
Consider efficiency of M as X , no. of Days E worked as D. $\therefore$ no. of days M worked= $\frac{D}{2}$

$\therefore$ Efficiency of E=$\frac{X}{2}$

$\therefore$ Contribution(M)=X $\times$ $\frac{D}{2}$ $\times$ 6 = 3XD [ $\because$ he has 6 hour shifts ]

$\therefore$ Contribution(E)=$\frac{X}{2}$ $\times$ D $\times$ 12=6XD  [ $\because$ he has 12 hour shifts ]

$\frac{ Contribution(M)}{Contribution(E)}$=$\frac{3XD}{6XD}$=$\frac{1}{2}$
1 votes
1 votes
0 votes
0 votes
Option B
edited by
Answer:

Related questions

8 votes
8 votes
1 answer
2
makhdoom ghaya asked Jan 20, 2017
2,323 views
Given $(9 \text{ inches}) ^{\frac{1}{2}} = (0.25\text{ yards}) ^{\frac{1}{2}},$ which one of the following statements is TRUE?$3$ inches = $0.5$ yards$9$ inches = $1.5$ y...
11 votes
11 votes
2 answers
3
makhdoom ghaya asked Jan 21, 2017
3,766 views
Two and quarter hours back, when seen in a mirror, the reflection of a wall clock without number markings seemed to show $1:30$. What is the actual current time shown by ...
7 votes
7 votes
3 answers
4
makhdoom ghaya asked Jan 20, 2017
2,748 views
The Venn diagram shows the preference of the student population for leisure activities.From the data given, the number of students who like to read books or play sports i...