52
Q:

An air conditioner can cool the hall in 40 miutes while another takes 45 minutes to cool under similar conditions. If both air conditioners are switched on at same instance then how long will it take to cool the room approximately ?

A) 18 minutes B) 19 minutes
C) 22 minutes D) 24 minutes

Answer:   C) 22 minutes



Explanation:

Let the two conditioners be A and B

 

'A' cools at 40min

 

'B' at 45min

 

Together = (a x b)/(a + b)

= (45 x 40)/(45 + 40)

= 45 x 40/85

= 21.1764

= 22 min (approx).

Q:

X and Y together can do a piece of work in 30 days. Y and Z together can do the work in 20 days. X starts the work and works for 15 days then Y takes that work and works for 27 days. Finally Z finishes the remaining work in 9 days. In how many days Y alone can complete the entire work?

 

A) 60 B) 45
C) 50 D) 65
 
Answer & Explanation Answer: A) 60

Explanation:
Report Error

View Answer Report Error Discuss

0 84
Q:

Both X and Y together can complete a work in 12 days and Y alone can complete the same work in 30 days. In how many days will X alone complete the work?

 

A) 15 B) 20
C) 18 D) 16
 
Answer & Explanation Answer: B) 20

Explanation:
Report Error

View Answer Report Error Discuss

0 123
Q:

A, B and C together can complete a work in 25 days. If the ratio of efficiency of A, B and C is 15 : 10 : 6 respectively, then in how many days C alone can complete the same work?

A) 727/6 B) 725/6
C) 775/6 D) 745/6
 
Answer & Explanation Answer: C) 775/6

Explanation:
Report Error

View Answer Report Error Discuss

0 241
Q:

Manish is four times as efficient as Puneet. Manish takes 90 days less than Puneet to complete a book. If both of them work together, then in how many days the book will be completed?

A) 28 B) 25
C) 24 D) 30
 
Answer & Explanation Answer: C) 24

Explanation:
Report Error

View Answer Report Error Discuss

2 283
Q:

Manish can complete a work in 21 days and Karan can complete the same work in 28 days. If both together work for 7 days, then what fraction of total work is left?

 

A) 3/5 B) 2/3
C) 7/12 D) 5/12
 
Answer & Explanation Answer: D) 5/12

Explanation:
Report Error

View Answer Report Error Discuss

2 256
Q:

20 boys do one fourth of work in 25 days. How many more boys will be required to complete the remaining work in 50 days?

 

A) 8 B) 10
C) 15 D) 20
 
Answer & Explanation Answer: B) 10

Explanation:
Report Error

View Answer Report Error Discuss

1 189
Q:

Sumit is 28% less efficient than Amit. If Amit can make a wall in 54 days, then Sumit can complete the same work in how many days?

 

A) 75 B) 70
C) 72 D) 76
 
Answer & Explanation Answer: A) 75

Explanation:
Report Error

View Answer Report Error Discuss

1 312
Q:

Vijay can do a work in 8 hours. Vijay and Puneet together can do the same work in 6 hours. Puneet and Sachin together can do the same work in 4 hours. Sachin alone can complete the same work in how many hours?

A) 22/5 B) 28/5
C) 24/5 D) 26/5
 
Answer & Explanation Answer: C) 24/5

Explanation:
Report Error

View Answer Report Error Discuss

1 252