CoCubes Time and Work Question and Answers Quiz-1

A and B one day work is 1/7.5
half of the work completed by a in 20 days
=> A takes 40 days to complete the work
A+B=1/7.5
B one day work =1/7.5-1/40
B can complete the work in 9.23 days =10 days

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

Consider this way....

Lanaya 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 Lanaya met her on the way.
That means both
met at 3.30 pm. So Lanaya 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.

Here if number of humans decrease by 10 has increasing the
number of days by 20

therefore,
40 humans for 40days
30 humans for 60days
20 humans for 80days

Ans: 80

or you can solve by ratio
40H : 40D --> 1:1
30H : 60D --> 1:2
20H : 80D --> 1:4

ans:80

let obese person 1 day work = x
fit person 1 day work = y
underweight person 1 day work = z
5 obese people 1 day work = 5x
5x=1/20
=>x=1/100
8 fit people 1 day work = 8y
8y=1/25
=>y=1/200
10 underweight people 1 day work = 10z
10z=1/30
=>z=1/300
a/c to ques, 2/100 + 6/200 + 5/300
=>(12+18+10)/600
=>1/15
ans is 15 days

3 robots finish painting a door in 8 days
1 robot = 24 days
1 robot 1 day work=1/24
Four men do the same job in 7 days
1 man = 28 days
1 man 1 day work=1/28
2 robot 1 day work=(1/24)*2=1/12
2 men 1 day work = (1/28)*2=1/14
2 robot and 2 men work together=1/12+1/14
=(7+6)/84
=13/84
no of days taken by 2 men and 2 robots=84/13
6\frac{6}{13}

Starting training 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 training at 4 PM

1. Dhoni 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 training = 300-210= 90 min
Starting again at 4 PM,he will finish his training at 5:30 PM

2. Virat can finish 3/7 of his homework in 90 min
He will finish 1 work in 90*(7/3) = 210 min
Therefore He finished his training at 3:30 PM

3.Yuvraj can finish 3/4 of his training in 210 min

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

Remaining time left for Yuvraj to complete his training =280 - 210 = 70 min
Starting to do training again at 4 PM,He will complete his work at
5:10 PM
Since Dhoni takes longer time to finish the training
(completing the work at 5:30 PM), hence they all can go to home at 5:30 PM.

the answer is approximately 230 gallons and if u want exact then
it comes 228.25

explanation is given below:
3 person together fill tank in 25 min hence,
calculate the time of person C that in how much time
he empty the tank so,

(1/A)+(1/B)-(1/C)=1/25

i.e, (1/30)+(1/35)-(1/C)=1/25 .......... we get,

1/C=23/1050,

while, its given the C can empty 5 gallon per min. therefore

(23/1050)=5

and capacity of tank will get if we solve above expression,
we get 228.25= 229

Modi 1 day spend time =40 min
Modi 20 days spend time =20*40min
= 800 min
so, convert it into hours= 800/60 hrs
13.33hrs

Time taken by both of them together to complete the work
= 1/(1/40 +1/30)
= 120/7 min