A single reservoir supplies the petrol to the whole city, while the reservoir is fed by a single pipeline filling the reservoir with the stream of uniform volume. When the reservoir is full and if 40,000 liters of petrol is used daily, the suply fails in 90 days.If 32,000 liters of petrol is used daily, it fails in 60 days. How much petrol can be used daily with out the supply ever failing?

Correct Answer: 20 hrs

Explanation:

Time taken by both Meghana and Ganesh to work together is given by =

t 1 x t 2

Where

$$\begin{gathered} t 1 = 32 h r s \\ t 2 = 12 1 2 h r s = 25 2 h r s \end{gathered}$$

 

Therefore, time took by both to work together = 

32 x 25 2 = 16 x 25 = 4 x 5 = 20 h r s

Correct Answer: 2

Explanation:

Let workdone 1 boy in 1 day be b

and that of 1 girl be g

From the given data,

4(5b + 3g) = 23

20b + 12g = 23 .......(a)

 

2(3b + 2g) = 7

6b + 4g = 7 ........(b)

 

Solving (a) & (b), we get

b = 1, g = 1/4

 

Let number og girls required be 'p'

6(7 x 1 + p x 1/4) = 45

=> p = 2.

 

Hence, number of girls required = 2

Correct Answer: 36 days

Explanation:

Given the ratio of efficiencies of P, Q & R are 3 : 8 : 5

Let the efficiencies of P, Q & R be 3x, 8x and 5x respectively

They can do work for 12 days.

=> Total work = 12 x 16x = 192x

 

Now, the required time taken by Q to complete the job alone = 162 x 8 x = 24days.

Correct Answer: 48/5 days

Explanation:

Amount of work K can do in 1 day = 1/16

Amount of work L can do in 1 day = 1/12

Amount of work K, L and M can together do in 1 day = 1/4

Amount of work M can do in 1 day = 1/4 - (1/16 + 1/12) = 3/16 ? 1/12 = 5/48

=> Hence M can do the job on 48/5 days = 9 (3/5) days  

Correct Answer: 3 pm

Explanation:

Work done by P and Q in the first two hours, working alternately

= First hour P + Second hour Q

? 1 4 + 1 12 = 1 3

work is completed in 2 hours

Then, the total time required to complete the work by P and Q working alternately=2 x 3= 6hours

Thus, work will be completed at 3pm.

Correct Answer: 17.5 days

Explanation:

Let the number of days be 'p' 

As the work is same, we know that

M 1 x D 1 x H 1 = M 2 x D 2 x H 2

Where M = Men, D = Days, H = Hours per day 

Here M1 = 9, D1 = 15, H1 = 7 

M2 = 6, D2 = p, H2 = 9 

=> 9 x 15 x 7 = 6 x p x 9 

=> p = 35/2 = 17.5 days.

Correct Answer: 123

Explanation:

We know that,  M 1 × D 1 W 1 = M 2 × D 2 W 2

Here M1 = 1, D1 = 6 min, W1 = 1 and M2 = M, D2 = 90 min, W2 = 1845

 

1 × 6 1 = M × 90 1845 

=> M = 123

Correct Answer: 6 days

Explanation:

From the given data,

12 children 16 days work,
One child?s one day work = 1/192.

8 adults 12 days work,
One adult?s one day?s work = 1/96.

Work done in 3 days = ((1/96) x 16 x 3) = 1/2

Remaining work = 1 ? 1/2 = 1/2

(6 adults+ 4 children)?s 1 day?s work = 6/96 + 4/192 = 1/12

1/12 work is done by them in 1 day.

1/2 work is done by them in 12 x (1/2) = 6 days.

Correct Answer: 2 days

Explanation:

work done=total number of person x number of days;
half of work done = 140 x 66;
For half of remaining work 25 extra men are added.
Therefore, total men for half work remaining = 140 + 25 = 165;
Let 2nd half work will be completed in K days;
140 x 66 = 165 x K
K = 122;
Hence, extra days => 122-120 = 2days.

Correct Answer: 1900

Explanation:

Given 2000 ---- 54 days

The provisions for 2000 men for 39 days can be completed by 'm' men for only 20 days.

i.e, 2000 ----- 39 days == m ---- 20 days

=> m x 20 = 2000 x 39

m = 3900

So total men for 20 days is 3900

=> 2000 old and 1900 new reinforcement.

Hence, reinforcement = 1900.