Model 1 Basics on Time & Work Section-Wise Topic Notes With Detailed Explanation And Example Questions
MOST IMPORTANT quantitative aptitude - 7 EXERCISES
-
Top 199+ Basic Time and Work Aptitude MCQs with Answers »
-
Top 200+ Time and Work Problem Solving By Formula Method »
-
New 189+ Time & Work MCQs Practice Test for BANK Exams »
-
Top 199+ Time & Work MCQs: Men Women Child for BANK Exam »
-
Top 199+ Time and Work Questions Test on Fraction of Work »
-
Top 199+ Time and Work Efficiency Based Aptitude MCQ Quiz »
-
New 299+ Time and Work Aptitude Test On Individual Wages »
The following question based on time & work topic of quantitative aptitude
(a) 3.6 days
(b) 2.5 days
(c) 3 days
(d) 4 days
The correct answers to the above question in:
Answer: (c)
A alone can complete the work in 42 days working 1 hour daily. Similarly, B will take 56 days working 1 hour daily.
A 's 1 day's work = $1/42$
B 's 1 day's work = $1/56$
(A + B) 's 1 day's work = $1/42 + 1/56 = {4 + 3}/168 = 7/168$
Time taken by (A + B) working 8 hours daily
= $168/{7 × 8}$ = 3 days
Using Rule 21If a man can do a certain work in '$d_1$' daysworking '$h_1$' hours in a days, while another man can do the same work in '$d_2$' days working '$h_2$' hours in a day. Whenthey work together everyday 'h' hours, then in how many days work will complete? Required time = $[{({h_1d_1}) × ({h_2d_2})}/{h_1d_1 + h_2d_2}] 1/h$
Here, $h_1$ = 7 hours, $h_2$ = 7 hours, $d_1$ = 6 days, $d_2$ = 8 days, h = 8 hours
Required Time = $[{({7 × 6}) × ({7 × 8})}/{7 × 6 + 7 × 8}] × 1/8$
= ${42 × 56}/98 × 1/8 = 2352/98 × 1/8 = 24/8$ = 3 days
Discuss Form
Read more basics on time and work Based Quantitative Aptitude Questions and Answers
Question : 1
A and B can complete a piece of work in 8 days, B and C can do it in 12 days, C and A can do it in 8 days. A, B and C together can complete it in
a) 7 days
b) 6 days
c) 4 days
d) 5 days
Answer »Answer: (b)
(A + B)’s 1 day’s work = $1/8$
(B + C)’s 1 day’s work = $1/12$
(C + A)’s 1 day’s work = $1/8$
On adding,
2 (A + B + C)’s 1 day’s work = $1/8 + 1/12 + 1/8$
${3 + 2 + 3}/24 = 8/24 = 1/3$
(A + B + C)’s 1 day’s work = $1/6$
Hence, the work will be completed in 6 days.
Method 2 :
Time = ${2xyz}/{xy + yz + zx}$
(Here, x = 8, y = 12; z = 8)
= ${2 × 8 × 12 × 8}/{96 + 96 + 64}$
${2 × 8 × 12 × 8}/256$ = 6 days.
Using Rule 5,
Time taken = ${2 × 8 × 12 × 8}/{8 × 12 + 12 × 8 + 8 × 8}$
= ${16 × 96}/{96 + 96 + 64} = {16 × 96}/256$ = 6 days
Question : 2
A and B can complete a piece of work in 30 days, B and C in 20 days, while C and A in 15 days. If all of them work together, the time taken in completing the work will be
a) 13$1/3$ days
b) 12$2/3$ days
c) 10 days
d) 12 days
Answer »Answer: (a)
Work done by (A + B) in 1 day = $1/30$
Work done by (B + C) in 1 day = $1/20$
Work done by (C + A) in 1 day = $1/15$
On adding,
Work done by 2 (A +B + C) in 1 day
= $1/30 + 1/20 + 1/15 = {2 + 3 + 4}/60$
= $9/60 = 3/20$
Work done by (A + B + C) in 1 day = $3/40$
(A + B + C) will do the work in $40/3 = 13{1}/3$ days
Using Rule 5,
Time taken = ${2 × 30 × 20 × 15}/{30 × 20 + 20 × 15 + 15 × 30}$
= $18000/{600 + 300 + 450}$
= $18000/1350 = 13{1}/3$ days
Question : 3
A and B can do a piece of work in 10 days. B and C can do it in 12 days. A and C can do it in 15 days. How long will A take to do it alone ?
a) 30 days
b) 40 days
c) 24 days
d) 20 days
Answer »Answer: (c)
(A+B)’s 1 day’s work = $1/10$
(B + C)’s 1 day’s work = $1/12$
(C + A)’s 1 day’s work = $1/15$
On adding all three,
2(A + B + C)’s 1 day’s work = $1/10 + 1/12 + 1/15$
= ${6 + 5 + 4}/60 = 15/60 = 1/44$
(A + B + C)’s 1 day’s work = $1/8$
A’s 1 day’s work = $1/8 - 1/12$
= ${3 - 2}/24 = 1/24$
A will complete the work in 24 days.
Using Rule 19,
A alone can do in = ${2 × x × y × z}/{xy + yz - zx}$
= ${2 × 10 × 12 × 15}/{10 × 12 + 12 × 15 - 15 × 10}$
= $3600/{120 + 180 - 150}$
= $3600/150$ = 24 days
Question : 4
A can do a piece of work in 4 hours; B and C can do it in 3 hours. A and C can do it in 2 hours. How long will B alone take to do it ?
a) 24 hours
b) 8 hours
c) 10 hours
d) 12 hours
Answer »Answer: (b)
A’s 1 hour’s work = $1/4$
(B + C)’s 1 hour’s work = $1/3$
(A + C)’s 1 hour’s work = $1/2$
C’s 1 hour’s work
= $1/2 - 1/4 = {2 - 1}/4 = 1/4$
and B’s 1 hour’s work
= $1/3 - 1/4 = {4 - 3}/12 = 1/12$
Hence, B alone can do the work in 12 hours.
Question : 5
A, B and C together can complete a piece of work in 30 minutes. A and B together can complete the same work in 50 minutes. C alone can complete the work in
a) 150 minutes
b) 80 minutes
c) 60 minutes
d) 75 minutes
Answer »Answer: (d)
Work done by (A + B + C) in 1 minute = $1/30$
Work done by (A + B) in 1 minute = $1/50$
Work done by C alone in 1 minute = $1/30 - 1/50$
= ${5 - 3}/150 = 2/150 = 1/75$
C alone will complete the work in 75 minutes.
Using Rule 4,
C alone can do in = ${xy}/{x - y}$
= ${50 × 30}/{50 - 30}$ = 75 minutes
Question : 6
A and B together can do a work in 10 days. B and C together can do the same work in 6 days. A and C together can do the work in 12 days. Then A, B and C together can do the work in
a) 8$2/7$ days
b) 5$5/7$ days
c) 28 days
d) 14 days
Answer »Answer: (b)
(A + B)’s 1 day’s work = $1/10$
(B + C)’s 1 day’s work = $1/6$
(C + A)’s 1 day’s work = $1/12$
Adding all three
2 (A + B + C)’s 1 day’s work = $1/10 + 1/6 + 1/12$
${6 + 10 + 5}/60 = 21/60 = 7/20$
(A + B + C)’s 1 day’s work = $7/40$
All three together will complete the work in $40/7 = 5{5}/7$ = days
Using Rule 5,
Time taken = ${2 × 10 × 6 × 12}/{10 × 6 + 6 × 12 + 12 × 10}$
= $1440/{60 + 72 + 120}$
= $1440/252 = 40/7 = 5{5}/7$ days
time & work Shortcuts and Techniques with Examples
-
Model 1 Basics on Time & Work
Defination & Shortcuts … -
Model 2 Formula method ‘M1D1W1 = M2D2W2’
Defination & Shortcuts … -
Model 3 Man leaves & joins
Defination & Shortcuts … -
Model 4 Working with Man, Woman, Child
Defination & Shortcuts … -
Model 5 Split & Fraction of work
Defination & Shortcuts … -
Model 6 Efficiency of the worker
Defination & Shortcuts … -
Model 7 Working with individual wages
Defination & Shortcuts …
Verbal Reasoning
Question & Answer Quiz
Non Verbal Reasoning
Question & Answer Quiz
Quantitative Aptitude
Question & Answer Quiz
Computer MCQ
Question & Answer Quiz
General English
Question & Answer Quiz
History GK
Question & Answer Quiz
Polity GK
Question & Answer Quiz
Geography GK
Question & Answer Quiz
Economy GK
Question & Answer Quiz
General Awareness GK
Question & Answer Quiz
Recently Added Subject & Categories For All Competitive Exams
Classification Reasoning MCQ For IBPS Clerk Prelims 2024
Most Important 100+ Classification based Verbal Reasoning Ability Multiple choice questions and answers PDF, Free New Mock tests For IBPS Clerk Prelims 2024
Continue Reading »
Ratio and Proportion Questions with Solutions, IBPS Clerk
New Ratio and Proportion Quants Aptitude based Multiple Choice Questions and Answers Practice Test Series, Quiz & Mock Test for IBPS Clerk Prelims 2024 Exam
Continue Reading »
Top Analogy Reasoning Ability For IBPS Clerk Prelims 2024
Most Important Analogy based Verbal Reasoning Multiple choice questions and answers practice quiz series PDF, Free New Mock tests For IBPS Clerk Prelims 2024
Continue Reading »
SSC STENO: Mensuration Area & Volume Questions Test PDF
Free Mensuration Area and Volume Aptitude-based Practice multiple questions with solutions, Quiz, Full Mock Test & PDF for SSC Steno (Grade C & D) 2024 Exam
Continue Reading »