Question

Two friends take a peice of work for Rs 960 one alone could it in 12 days and other can do it in 16 days. If with the assistance with an expert they finished it in 4 days then how much remuneration should expert get
A.Rs700
B.Rs550.
C.Rs400
D.Rs350

Please answer with explanation
Please...

Answer 1

Hello. Your answer is C)Rs.400

Explanation:-

For The first friend: He completes the work in 12 days. So he charges Rs.960 only if he works for 12 days full. That means he charges Rs. 80 for each day.
The work was completed in 4 days. Therefore, his total charge : 80*4=320.

similarly,
For Second: Daily Charge: 960/16= 60 Rs.
Therefore, Total charge for 4 days: 60*4=240

Therefore, the renumeration for the expert : 960-(240+320)
= 960-560
=400 Rs.

Thank you!!

Answer 2

Given:

The piece of work can earn Rs 960.

One friend can finish the work in 12 days alone.

The other friend can finish the work in 16 days alone.

The engaged a expert and they finished it in 4 days.

To Find:

The amount the expert should get

Solution

Find the amount of work one friend can do in a day:

He finished the work in 12 days

$\text{1 day} = \dfrac{1}{12} \text{ of the work}$

Find the amount of work the other friend can do in a day:

He finished the work in 16 days

$\text{1 day} = \dfrac{1}{16} \text{ of the work}$

Find the amount of work the 2 friends and the expert can finish in a day:

They can finish the work in 4 days

$\text{1 day} = \dfrac{1}{4} \text{ of the work}$

Find the amount of work both friends can finish in a day:

$\text{Both Friends } = \dfrac{1}{12} - \dfrac{1}{16}$

$\text{Both Friends } = \dfrac{7}{48}$

Find the amount of work the expert can finish in a day:

$\text{Expert } = \dfrac{1}{4} - \dfrac{7}{48}$

$\text{Expert } = \dfrac{5}{48}$

Find the ratio of their efficiency:

$\text{One Friend}: \text{Other Friend}: \text{Expert}: = \dfrac{1}{12 } : \dfrac{1}{16 } : \dfrac{5}{48 }$

$\text{One Friend}: \text{Other Friend} : \text{Expert}: = \dfrac{4}{48 } : \dfrac{3}{48 } : \dfrac{5}{48 }$

$\text{One Friend}: \text{Other Friend} : \text{Expert}: = 4 : 3 : 5$

Find the amount the expert will get:

One Friend : Other Friend : Expert : 4 : 3 : 5

One Friend = 4x

Other Friend = 3x

Expert = 5x

Total = 4x + 3x + 5x

Total = 12x

12x = Rs 960

1x = Rs 80

5x = 80 x 5

5x = Rs 400

Answer: (C) Rs 400