Work from Days section will ask you questions in which you will have to calculate the amount of work that we can perform in some time. In a similar manner to the concept of days from work, the work from days section is easily solved by the application of some basic concepts and the formulae that we will develop. Here we have solved examples and all the important concepts that you may have to answer while solving this section. Let us see.

Work from Days

Let us start by developing the formula for this section.
First, we have the formula of the work. Where work is the numerical value of the task.  Work =  Number of days (Time) (T or D) × Number of men (M). In other words, W = D × M.
Suppose w1 is the work done in the first case and w2 in the second case. Also, let us suppose that T1 is the number of days that the first person takes and T2 is the number of days that the second term takes. Also, let N1 and N2 represent the number of people that undertake each task respectively. Then the ratio of the work done in the first task to the work done in the second task is equal to w1/w2 = (T1 × N1)/(T2 × N2). Let us see some examples of getting work from days.

Solved Example

Example 1: Ten people can cut 20 trees in 2 days. If twenty people work for two months, then how many trees will be cut during this time?
A) 1330 trees               B) 1223 trees            C) 1220 trees               D) 1222 trees
Answer: We will use the formula w1/w2 = (T1 × N1)/(T2 × N2) that we have developed just above. Here w1 = 20, T1 = 2 and N1 = 10.
Similarly, we have w2 = ? , T2 = 61 days, and N2 = 20. Substituting these  values in the equation above, we have:
w1/w2 = (T1 × N1)/(T2 × N2). In other words we can say: 20/w2 = (2×10)/(61×20).
Solving this we can say that w2 = 1220 trees.
We can use the same formula to solve similar questions.  Let us now see an important concept that will simplify a lot of our problems. The concept of efficiency in work. Hence the correct option is C) 1220 trees.

Efficiency Of Work

Work from Days
The efficiency is the amount of work that a person can do in some certain time.  For example, consider the following example:
Example 2: What is the efficiency of a person who finishes his job in 5 days?
Answer: As per the question, the number of days this person takes to complete the work = 5
Therefore we can say that he does 1/5th of the work per day. This when we convert it into percentage = 100/5 = 20%. Therefore, his efficiency is 20%.
We can use the efficiency to solve many problems in a very short time. Let us see how.
Example 3: A person ‘A’ can do a job in 10 days. Another person ‘B’ can do the same job in 5 days. In how many days will they complete this job if they work together?
Answer: As per the question, we have A’s efficiency = 10% and B’s efficiency = 20%.
Therefore when they work together, their efficiency  is = A+ B = 10 + 20 = 30%
This means, in one day A and B together can do 30% of work. Therefore, the number of days it will take A and B together to do 100% of the work = 100/30 = 3.33 days.