Q1. A contractor undertakes to make a mall in 60 days and he employs 30 men. After 30 days it is found that only one- third of the work is completed. How many extra men should he employ so that the work is completed on time?
A. 20men
B. 25men
C. 30men
D. 40men
Answer: Option C
Explanation:
Let total work is w and it is given that one-third of the work is completed after 30 days. Means
M*D = 30*30 = [latex]\frac{w}{3}[/latex], so total work = 30*30*3
2700 = 30*30 + (30 + p)*30, so we get P = 30 (p = additional men)
Q2. 50 men could complete a work in 200 days. They worked together for 150 days, after that due to bad weather the work is stopped for 25 days. How many more workers should be employed so as to complete the work in time?
Answer: Option C
Explanation :
Let additional workers be P,
(50*150)/(50*200) = [latex]\frac{3}{4}[/latex] of the work is already completed and now only 1/4 of the work is to be done. So,
[latex]\frac{1}{4}[/latex] = [latex]\frac{(50 + P) * 25)}{50*200}[/latex], solve for p, we get P = 50
Q3. P and Q were assigned to do a work for an amount of 1200. P alone can do it in 15 days while Q can do it in 12 days. With the help of R they finish the work in 6 days. Find the share if C.
A. 100
B. 120
C. 140
D. 160
Answer: Option B
Explanation :
[latex]\frac{1}{15}[/latex] + [latex]\frac{1}{12}[/latex] + [latex]\frac{1}{c}[/latex] = [latex]\frac{1}{6}[/latex], we got C = 60 (it means C will take 60 days to complete the work alone)
so ratio of work done by P:Q:R = 4:5:1
so c share = ([latex]\frac{1}{100}[/latex])*1200 = 120
Q4. P does half as much work as Q in three-fourth of the time. If together they take 24 days to complete the work, how much time shall P take to complete the work?
A. 50 days
B. 60 days
C. 70 days
D. 80 days
Answer: Option B
Explanation :
Let Q take x days to complete the work, so P will take 2* [latex]\frac{3}{4}[/latex] of X day to complete the work i.e. 3x/2 days
[latex]\frac{1}{x}[/latex] + [latex]\frac{2}{3x}[/latex] = [latex]\frac{1}{24}[/latex], we get x = 40 days, so P will take = [latex]\frac{3}{2}[/latex] of 40 = 60 days
Q5. Neha takes 5 hours to type 40 pages while sunil takes 6 hours to type 60 pages. How much time will they take working together on different computer to type an assignment of 180 pages.
A. 5hr
B. 7hr
C. 9hr
D. 10hr
Answer: Option D
Explanation :
In one hour number of pages type by neha = [latex]\frac{40}{5}[/latex] = 8 and similarly for sunil it is [latex]\frac{60}{6}[/latex] = 10.
Now to type 180 pages they will take, (8 + 10)*T = 180, T = 10 hours