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 4 of 10.

Shubham Singh said:   8 years ago
A+B completes work in 30 days, so,

=>unit of work done by both A and B in 1 day = 1/30,
Consider that total work done by both A and B = 30 units,
So,in 1 day = 1 unit work is done,
Since 1 day = 1 unit of work then A do 16 units of work,
Remaining work = 30-16 = 14 units,
This 14 units of work is done by B in remaining 28 days(44 days-16 days).

If we see read the question we get that "the total number of days required by B to complete the total 30 units" is asked.
So we do like this,
for 28 days = 14 units,
x days = 30 units,
we get 14*x = 28 * 30,
=>x = 28*30/14,
=>x=60 days.

Puneet negi said:   8 years ago
A + b=30.
Let the efficiency of a and b is 1.
Then total work will be 30*2=60.
A did 16 work then remaining work is,

60-16=44 which will be completed by b in 44 days so B's actual efficiency is 1 so B will finish 60 work in 60 days.

Tapash Dey/LMG said:   8 years ago
My method:- Mixture

A -------------- B
16 -------------- 44
30 --------------
14 : 14
1 : 1

So, B completed the whole work( means A's work +B's work alone)=(16 x1 +44 x 1) = 60 days.

Vignesh B K said:   8 years ago
Consider like this,

A and b completes a work in 30days. So this means both individually work for 30 days. Let us assume they do some bottles. If 60 bottles they have to do. It can be 30 bottles each or it can be 45 and 15 bottles or 40 & 20. So it depends upon each one capability.

So we can frame an equation like this,

30x+30y=1 (where x and why are the number of bottles per day. It is equated to 1 because for a day we are calculating).

Similarly, if A works for 16 days and B work for the 44 days,

So it will be 16x+44y = 1.

Solving and we will arrive at the answer.

Sayyidah shah said:   8 years ago
Let work done by A in 1 day be a and the work done by B in 1 day be;

A and B together can do a piece of work in 30 days.
=> Work done by A and B in 1 day = 1/30.
a + b = 1/30...........(1),

Work done by A in 16 days + work done by B in 44 days = 1.
16a + 44b = 1 ...........(2).

Solve (1) and (2)

Multiply equation (1) with 16 => 16a + 16b = 16/30=8/15 .......(3)
Subtract equation (3) from (2) => 28b = 1 - 8/15=7/15,
b = 7/15 * 1/28=1/60.

i.e., B alone needs 60 days to finish the work.

Sayyidah shah said:   8 years ago
1 represents whole work..i.e
16X + 44Y =1
Means A having work for 16 days and B remaining in 44 so whole work is represented by 1 always.

Supplementary argument.
Like wise if A work 4/15 ( 16/60) and B remaining work 11 /15 ( 1- 4/15) which is done in 44 days.

4 / 15 + 11/15= 1 makes whole work.
Here we write X for A because we don't know As whole work alone and similarly Y for B too. The only thing we know is the remaining work.

Hope understand better now.

Ebrahim said:   9 years ago
Guys this is very very simple.

Time taken by A + B : 30 days.
They didn't mention the efficiency of neither A nor B.
So we can take 50/50 efficiency.
For example
Total: 30 candles.
A+B making 30 candles in 30 days.

So, A alone makes 30 candles in 60 Days.

Aakash said:   9 years ago
2 workers A + B together could finish a work in 8 days they work together for 6 days & A left the works the remaining works was completed by B alone in 6 days. How many days would each take to complete the individual?

How to solve this problem?

Bisu said:   9 years ago
Can somebody solve it in the shortcut?

Dhakshina said:   9 years ago
Given X + Y =30.

They never mentioned any efficiency (like B is twice as good).

Assume that they are equal efficiency.

So A Did only 16 days work and B completed remaining work in 44 days.

Therefore total work of B is 44 + 16 = 60.

Total work of A is also 60.


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