Quiz-1

1 man\'s 1 day work=1/24
1 boy\'s 1 day work=1/28
2 men\'s 1 day work=(1/24)*2=1/12
2 boys \'s 1 day work = (1/28)*2=1/14
2 men and 2 boys work together=1/12+1/14
=(7+6)/84
=13/84
no of days taken by 2 men and 2 boys=84/13
6 6/13
Option (d) is the ans

Time taken by both pipes together to fill the tank = 1/(1/40 +1/30) = 120/7 min

Time taken by Rita to water plant in 1 day = 40 min

time taken by Rita to water plant in 20 days = 40 min × 20
=800 min
=13 hr 20 min

Starting homework at 12 PM and Taking a break at 3:30 PM,
we came to know that each of them have already spent
3 hrs and 30 minute i.e 210 min
After taking break, they started to do their homework at 4 PM
1. Rajesh can finish 1/5 of his work in 1 hr. i.e in 60 min
He can finish 1 work in 60* 5 = 300 min
Remaining time to complete his hm work = 300-210= 90 min
Starting again at 4 PM,he will finish his homework at 5:30 PM
2. Sema can finish 3/7 of her homework in 90 min
She will finish 1 work in 90*(7/3) = 210 min
Therefore she finished her work at 3:30 PM
3.
Ramya can finish 3/4 of her work in 210 min

She will finish 1 work in 210*(4/3 ) min= 280 min

Remaining time left for Ramya to complete her work =280 - 210 = 70 min
Starting to do homework again at 4 PM, she will complete her work at 5:10 PM
Since Rajesh takes a longer time to finish the work (completing the work at 5:30 PM), hence they all can start to play at 5:30 PM. That\'s the only time they all will meet

Ans : 15days
For Skilled
5 workers --------20 days
5 workers 1 day work= 1/20
1 worker\'s 1 day work= 1/(5*20)

Similarly,
For Semi-Skilled------
1 worker\'s 1 day work= 1/(8*25)

For Unskilled------
1 worker\'s 1 day work= 1/(10*30)

For 2 skilled,6 semi-skilled and 5 unskilled
workers
One day work= 2*[1/(5*20)] +6*[1/(8*25)] + 5*[ 1/(10*30)] = 1/15
Therefore no. of days taken= 15

nDays = k1 * nCows + k2
thus,
40 = 40k1 + k2
60 = 30k1 + k2
Solving for k1, k2;
k1 = -2, k2 = 120
Therefore,
in case of 20 cows:
nDays = 20*-2 + 120 = 80 days

Consider this way....

Shanti walked and as a result she saved the total driving hours= 1
Which means her mom saves half an hour each going up and
down since Santi met her on the way.
That means both
met at 3.30 pm. So Shanti walked what the distance in 2.5 hrs
(from 1 pm to 3.30 pm) what her mom would have driven for half an hour.

So the ratio of their speeds are 0.5: 2.5 i.e. 1:5.

The clue lies in considering the to and fro distance.

Hope it is clear now.
:)

Inlet pipe fills the tank in 5 hr and outlet pipe empties the tank
in 36 hr.
So inlet pipe is 36/5 = 7.2 times efficient than , ensure that the
an outlet pipe.
Therefore , in order to tank never overflows , we will need total
8 outlet pipes.
Already we have 1 outlet pipe , thus we need only (8-1) = 7 outlet pipes

10 days

1/A + 1/B = 2/15 or (A+B)/AB= 2/15 ----(i)

(1/2)/(1/A) + (1/2)/(1/B) = 20 or A/2 + B/2 = 20 or A+B= 40 ----(ii)
Substituting A+B= 40 from (ii) in (i), we get AB= 300
Now finding the factors of 300, whose sum is 40, we have 10 and 30
As B is more efficient than A, B can do the work in 10 days.