Aptitude - Time and Work - Discussion

Discussion Forum : Time and Work - General Questions (Q.No. 30)
30.
A and B together can do a piece of work in 30 days. A having worked for 16 days, B finishes the remaining work alone in 44 days. In how many days shall B finish the whole work alone?
30 days
40 days
60 days
70 days
Answer: Option
Explanation:

Let A's 1 day's work = x and B's 1 day's work = y.

Then, x + y = 1 and 16x + 44y = 1.
30

Solving these two equations, we get: x = 1 and y = 1
60 60

B's 1 day's work = 1 .
60

Hence, B alone shall finish the whole work in 60 days.

Discussion:
97 comments Page 3 of 10.

Jeyasurya said:   7 years ago
B finishes the remaining work in 44 days.
A finishes the work in 16 days,
So, B alone, 44 + 16 = 60 days.
(2)

Deepak said:   7 years ago
A+B can do a work in 30 days.
One day work done by A =1/A.
One day work done by B=1/B.
1/A+1/B=1/30.

A worked for 16 days.
So one day work done by A =16/A.
Remaining work =1-16/A.
One day work done by B=1/B.
In 44day work done by B=44/B.
1-16/A=44/B.

16/A+44/B=1-----> eq1
1/A=1/30-1/B----> eq2

16(1/30-1/B)+44/B=1.
16/30+(44_16/B)=1,
16/30+28/B=1,
28/B=1-16/30,
28/B=30-16/30,
28/B=14/30,
28*30=14B,
B=840/14=60.

B shall finish whole work in 60 days.

Tufail Ashraf Bhat said:   8 years ago
A+B do whole work in 30 days(100% of work or Complete).
A+B's1 day work =1/30.
Let us take assumption as usual.
A's 1 day work = x , & B's 1 day work = y.
=> x+y=1/30 ------------ eq1.
Now people got confused by;

This 16x +44y =1.
(Ans. It is equal to 1 coz 1 here means 100% or mathematically 1/1=1 and in eq1 1/30 means 1/30 100%work--1 divided into 30 parts has been done in 1 day 1/30%=3.3%).
And simply 1 means 100%. 1/1*%. Or 1/1x100.
(1)

Biswaranjan mohapatra said:   8 years ago
x+y=30.
so if A do a work in x days then B do it in 30- x days.
A's 1-day work is 1/x.
B's 1-day work is 1/y.
Both 1-day work is 1/30.

So according to question.
1/x + 1/30-x = 1/30.
Solve it and find x.

Manish said:   8 years ago
Don't consider x & y only consider x.
We know 16 days work of A + 44 days of B = total 1 work.
let work be x by both A & B.
now 16 days of x+44 days of x=1 work.
60 days x=1 work.
x=1/60.

Now find total work of B.
first find how much worked for 44 days ie-44*1/60=11/15.
now for 44 days he completed work of 11/15.
how many days he need to complete 1 work (total work) .
44*15/11=60 days.

Priti said:   8 years ago
Please tell me how to solve the equation of x and y in detail?

Naman said:   8 years ago
Thanks @Sandeep.

Sandeep said:   8 years ago
LCM Method

(A + B) 30 = 16A + 44B

14A = 14B
A/B = 1/1

So one day work

A = 1 unit
B = 1 unit

Total work = 30 x (1 + 1) = 60 units
Time taken by B = 60/1 = 60 days.

Subhant said:   8 years ago
Solving the equations is tiresome brothers.
Instead take like

16a +44 b = 30 a + 30b.
a/b = 1/1
So if a one day work is 1 and b one day work is one and when they work together they do 2 units of work every day.

this means there is 30x2 = 60 units of work.

B can do it in = (total unit of work)/(B's one day work) = 60 days.

Sagar parida said:   8 years ago
Please, anyone help me out from this question--.

A and B can do a work together in 10 days, B and C can do the same work in 18 days, if A starts the work and after working 5 days B do the work for 15 days and remaining work in done by C than find in how many days will C complete the work alone?


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