Practice Questions:
6 men can do a piece of work in 12 days.
To do the work in 18 days, the men needed are,
Days increased and the number of men needed will become less.
So, it's inverse proportion.
6/x = 18/12
72 = 18x
x = 72/18 = 4
Number of men needed is 4.
Question 1:
Raju can do 25% of a piece of work in 5 days. How many days will he take to complete the work ten times?
25% of the work can be done in 5 days.
So, total work i.e., 100% of the work can be done in 20 days.
Hence, it will take 200 days to complete the work ten times.
So, total work i.e., 100% of the work can be done in 20 days.
Hence, it will take 200 days to complete the work ten times.
Question 2:
6 men can do a piece of work in 12 days. How many men are needed to do the work in 18 days.
6 men can do a piece of work in 12 days.
To do the work in 18 days, the men needed are,
Days increased and the number of men needed will become less.
So, it's inverse proportion.
6/x = 18/12
72 = 18x
x = 72/18 = 4
Number of men needed is 4.
Question 3:
8 men can do a work in 12 days while 20 women can do it in 10 days. In how many days can 12 men and 15 women complete the same work.
Total work = 8 * 12 = 96 (man days) ; 20 * 10 = 200 (woman days)
96 man days = 200 woman days
1 man day = 200 / 96 = 2.0833 woman days
12 men + 15 women = (12 * 2.0833) + 15
Work done = 24.999 + 15 = 25 + 15 = 40 woman days
Hence, 40 * number of days = 200
Number of days to complete the work = 200 / 40 = 5 days.
96 man days = 200 woman days
1 man day = 200 / 96 = 2.0833 woman days
12 men + 15 women = (12 * 2.0833) + 15
Work done = 24.999 + 15 = 25 + 15 = 40 woman days
Hence, 40 * number of days = 200
Number of days to complete the work = 200 / 40 = 5 days.
Question 4:
Subhash can copy 50 pages in 10 hours; Subhash and Prakash together can copy 300 pages in 40 hours. In how much time can Prakash copy 30 pages?
Subhash = 50 pages in 10 hours
Prakash + Subhash = 300 pages in 40 hours
So, Subhash = 200 pages in 40 hours and Prakashu = 100 pages in 40 hours
30 pages of Prakash = 30 % = 30/100 * 40 = 12 hours.
Prakash + Subhash = 300 pages in 40 hours
So, Subhash = 200 pages in 40 hours and Prakashu = 100 pages in 40 hours
30 pages of Prakash = 30 % = 30/100 * 40 = 12 hours.
Question 5:
Manoj takes twice as much time as Anjay and thrice as much as Vijay to finish a piece of work. Together they finish the work in 1 day. What is the time taken by Manoj to finish the work?
Manoj = twice of Anjay and thrice of Vijay
Manoj + Anjay + Vijay = 1 day
Let the time taken by, Anjay be 3t days, Vijay be 2t days and Manoj be 6t days.
So, 1/2t + 1/3t + 1/6t = 1
t = 1
So, time taken by Manoj = 6t = 6 * 1 = 6 days.
Manoj + Anjay + Vijay = 1 day
Let the time taken by, Anjay be 3t days, Vijay be 2t days and Manoj be 6t days.
So, 1/2t + 1/3t + 1/6t = 1
t = 1
So, time taken by Manoj = 6t = 6 * 1 = 6 days.
Time to Think:
Sashi can do a piece of work in 25 days and Rishi can do it in 20 days. They work for 5 days and then Sashi goes away. In how many more days will Rishi finish the work?
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