Ratio, Proportion and Partnership
- Ratio, Proportion & Partnership
- CRE 1 - Ratio
- CRE 2 - Proportion
- CRE 3 - Partnership
- PE 1 - Ratio
Percentage, Profit & Loss
- Percentage
- Profit & Loss
- CRE 1 - Percentage
- CRE 2 - Percentage Change
- CRE 3 - Successive Percentage Change
- CRE 4 - Profit & Loss
- CRE 5 - Discount
- PE 1 - Percentage
Simple and Compound Interest
- Simple & Compound Interest
- CRE 1 - Simple Interest
- CRE 2 - Compound Interest
Average, Mixture & Alligation
- Average
- Mixture & Alligation
- CRE 1 - Simple Average
- CRE 2 - Numbers Added/Removed
- CRE 3 - Weighted Average
- PE 1 - Average
- PE 2 - Average
Time and Work
- Time and Work
- CRE 1 - Basics
- CRE 2 - Working in Shifts
- CRE 3 - Payments
- CRE 4 - Man Days (single group of people)
- CRE 5 - Man Days (multiple groups of people)
- CRE 6 - Pipes & Cisterns
- PE 1 - Time and Work
Time, Speed and Distance
- Time, Speed and Distance
- CRE 1 - Basics
- CRE 2 - Relative Speed
- CRE 3 - Trains
- CRE 4 - Boats & Streams
Numbers
- CRE 1 - Simplification
- PE 1 - LCM & HCF
- PE 2 - LCM & HCF
- PE 3 - Unit's Digit
Indices & Surds
- CRE 1 - Indices
- CRE 2 - Surds
Linear & Quadratic Equations
Permutations, Combinations & Probability
Geometry, Mensuration & Trigonometry
- Geometry Basics
- CRE 1 - Geometry Basics
- CRE 2 - Triangles
- CRE 3 - Circles
- CRE 4 - Mensuration
- CRE 5 - Trigonometry
Data Interpretation
- CRE 1 - Tables
Arrangements, Ranking & Ordering
- PE 1 - Arrangements
- PE 2 - Ranking
- PE 3 - Ordering
Analogy & Odd One Out
- PE 1 - Word Analogy
- PE 2 - Word Analogy
- PE 3 - Alphabet Analogy
- PE 4 - Numbers Analogy
- PE 5 - Odd One Out
Number & Alphabet Series
- PE 1 - Number Series
- PE 2 - Alphabet Series
Coding & Decoding
- PE 1 - Coding & Decoding
Clocks & Calendars
- PE 1 - Clocks
- PE 2 - Calendars
Venn Diagram
- CRE 1 - Venn Diagram
- CRE 2 - Venn Diagram
progression
Mathematical Operations
- PE 1 - Mathematical Operations
Dice & Cubes
- PE 1 - Dice
Visual Reasoning
Blood Relation & Direction Sense
- PE 1 - Blood Relation
- PE 2 - Direction Sense
General Knowledge & Current Affairs
Syllogisms

CRE 1 - Basics | Time and Work

1. CRE 1 - Basics | Time and Work

A alone can do a piece of work in 10 days and B alone can do it in 15 days. How long will both A and B together take to finish the same work?

A.
6
B.
5
C.
25
D.
6.5

Answer: Option A

Explanation :

Unitary Method:

A’s 1 day’s work = $\frac{1}{10}$

B’s 1 day’s work = $\frac{1}{15}$

∴(A+B)'s 1 day' s work $\frac{1}{10} + \frac{1}{15}$ = $\frac{5}{30}$ = $\frac{1}{6}$

∴ Both together can finish the work in $\frac{1}{1 / 6}$ or 6 days

LCM Method:

Let the total work to be done = LCM(10, 15) = 30 units

A can complete this work in 10 days, hence A’s efficiency = 30/10 = 3 units/day

B can complete this work in 15 days, hence A’s efficiency = 30/15 = 2 units/day

Combined efficiencies of A and B = 3 + 2 = 5 units/day

Time taken by A and B together to complete the work = 30/5 = 6 days.

Hence, option (a).

2. CRE 1 - Basics | Time and Work

A and B together can complete a piece of work in 45 days, while A alone can complete it in 60 days. So, B alone can complete the work in how many days?

A.
64 days
B.
46 days
C.
48 days
D.
180 days

3. CRE 1 - Basics | Time and Work

A can do a piece of work in 16 days. B is 60% more efficient than A. Find the number of days it takes B to do the same piece of work?

A.
10
B.
22
C.
$5 \frac{1}{7}$
D.
8

Answer: Option A

Explanation :

A’s 1 day’s work = $\frac{1}{16}$ ;

B is 60% more efficient than A, hence B can do 60% more work in a day than A can.

∴ B’s 1 day’s work = $\frac{1}{16} \times 1.6$ = $\frac{1}{10}$

∴ B can do the work in 10 days

Hence, option (a).

4. CRE 1 - Basics | Time and Work

A is thrice as good a workman as B and takes 20 days less to do a piece of work than B. B alone can do the whole work in:

A.
20 days
B.
24 days
C.
30 days
D.
36 days

5. CRE 1 - Basics | Time and Work

A can do as much work in 3 days as B can in 2 days and C can do as much work in 5 days as much work as B can in 6 days. What time will C take to complete a work that A can complete in 36 days?

A.
16 days
B.
24 days
C.
30 days
D.
20 days

6. CRE 1 - Basics | Time and Work

‘A’ alone can complete a piece of work in 16 days. Work done by B alone in one day is half of the work done by A alone in one day. In how many days can the work be completed, if A and B work together?

A.
38/3
B.
34/3
C.
32/3
D.
40/3
E.
None of thhese

7. CRE 1 - Basics | Time and Work

P is thrice as efficient as Q and R is twice as efficient as P. What is the ratio of the number of days taken by P, Q and R, when they work individually?

A.
6 : 3 : 1
B.
3 : 1 : 6
C.
2 : 1 : 6
D.
3 : 6 : 1
E.
2 : 6 : 1

8. CRE 1 - Basics | Time and Work

Akanksha can type 20 pages in 5 minutes. Mary can type 10 pages in 10 minutes. Working together, how many pages can they type in 30 minutes?

A.
30
B.
40
C.
50
D.
130
E.
150

9. CRE 1 - Basics | Time and Work

Amit can do a work in 12 days and Sagar in 15 days. If they work on it together for 4 days, then the fraction of the work that is left is:

A.
3/20
B.
3/5
C.
2/5
D.
2/20

Answer: Option C

Explanation :

Work done by Amit in one day = $\frac{1}{12}$
Work done by Sagar in one day = $\frac{1}{15}$

In one day, Amit and Sagar can do = $\frac{1}{12}$ + $\frac{1}{15}$ = $\frac{3}{20}$ ^th

Hence, in 4 days they will complete $4 \times \frac{3}{20}$ = $\frac{3}{5}$ ^th of the work.

Hence, amount of work remaining after 4 days = 1 - $\frac{3}{5}$ = $\frac{2}{5}$ .

Hence, option (c).

10. CRE 1 - Basics | Time and Work

Aakash alone can do a piece of work in 15 days. Bikash alone can do it in 24 days. They complete the work together. If the total wages for the work is Rs. 312, how much should Aakash be paid?

A.
Rs. 128
B.
Rs. 144
C.
Rs. 164
D.
Rs. 180
E.
Rs. 192

CRE 1 - Basics | Time and Work

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