Directions: Refer the following data to answer the questions given below.
In 20 kg fresh grapes, 18 kg is water and 2 kg is dried grapes. But these must contain 20% of water of total weight.
Hence 2/0.8 = 2.5 kg.
Directions: Refer the following data to answer the questions given below.
Let the average age of people aged 51 years and above be x years.
Let the average age of people aged below 51 years be y years.
Let the number of people aged below 51 years be N.
Given, the average age of all the people in the apartment complex is 38 years.
Therefore,
x?30?y?N? 38 ….(1)
30?N
We want to maximize y, which occurs when x is minimum i.e. for x=51.
Substituting the value of x in (1) we get
390=N×(38-y)
Again, when y is maximum, N is also maximum i.e. 39
Therefore maximum value of y = 28.
Directions: Read the following information to answer the question.
Solution:
12 men in 36 days can do a work.
1 man in a day can do 1/12×36 work.
8 men in 20 days can do 8×20/12×36=10/27 work.
Similarly, we find that 20 women in 20 days can do 10/27 work.
Remaining work =7/27
Now, because in 60 days a work is done by 20 women.
In 1 day a work done by 20×60 women.
In 4 days 7/27
work is done by 20×60×7/27×4
= 70 women.
Directions: Read the following information to answer the question.
Solution:
Let 'a' be the number of days in which A can do the job alone. Therefore, working alone, A will complete (1/a)th of the job in a day.
Similarly, let 'b' be the number of days in which B can do the job alone. Hence, B will complete (1/b)th of the job in a day.
Working together, A and B will complete (1/a+1/b)th of the job in a day.
The problem states that working together, A and B will complete the job in 7.5 or 15/2 days. i.e they will complete 2/15)th of the job in a day.
Therefore, 1/a+1/b=2/15 ...... (1)
From the question, we know that if A completes half the job working alone and B takes over and completes the next half, they will take 20 days.
As A can complete the job working alone in 'a' days, he will complete half the job, working alone, in
a/2 days.
Similarly, B will complete the remaining half of the job in b/2 days.
Therefore, a/2+b/2=20
⇒ a+b=40 or a=40–b ...... (2)
From (1) and (2) we get,
{1/40−b}+1/b=2/15
⇒ 600=2b(40−b)
⇒ 600=80b−2b2
⇒ b2−40b+300=0
⇒ (b−30)(b−10)=0
⇒ b=30 or b=10.
If b=30, then a=40−30=10 or
If b=10, then a=40−10=30.
As A is more efficient than B, he will take lesser time to do the job alone. Hence A will take only 10 days and B will take 30 days.
Note: Whenever you encounter work time problems, always find out how much of the work can 'A' complete in a unit time (an hour, a day, a month etc). Find out how much of the work can be completed by 'B' in a unit time. Then add the amount of work done by A and B to find the total amount of work that will be completed in a unit time.
If 'A' takes 10 days to do a job, he will do (1/10)th of the job in a day.
Similarly, if (2/5)th of the job is done in a day, the entire job will be done in 5/2days.
Directions: Read the following information to answer the question.
Solution:
C’s one day’s work =(1/3)−(1/6+1/8)=1/24
Therefore, A:B:C = Ratio of their one day’s work =1/6:18:1/24
=4:3:1
A’s share =Rs.600×(4/8)=300
B’s share =Rs.600×(3/8)=225
C’s share =Rs[600−(300+225)]= Rs 75