Aptitude - Time and Work - Discussion

A is 30% more efficient!!
So ratio will be 130:100 :: 23:x.
So x = 230/13
Final answer comes to 10.
Can someone plz confirm this?

Given that A is 30% efficient than B then

A=130% and b=100%
so 130%=23 days
then 100%=23*100/130=230/13
so B' 1 day work=13/230 and A' 1 day work=1/23
(A+B) one day work=(1/23+13/230)=10
so the answer is D

Hello its very easy ....
see
A is 30% more efficient than B
that means A=130% speed B=100% speed assume, then convert into ratio format because 13:10 it's work, now we can convert to days 10:13 (this ratio for separate man work days)

we must now ratio formula then only we understand
this method
A:B=A:B
also we write A:B::A:B

now apply
10:13::23:X ( Formula A:B::c:d =>A*d=B*c )

now we can solve that
10X=13*23
X=(13*23)/10
now we got X value X =299/10 days for B
B 1 day work is 299/10
then as usually go next steps

Thanks to Elumalai.

Say B does the work in x days.
A is 30% more efficient than B.

That means A will do it in x- (30*x/100) which is equal to 23 days.
So,

X-30*x/100=23.

70x=2300.

X=230/7.

So A and B together will work in.

[1/23+7/230]y=1.

Y=230/17=13.53=13 days (approx).

Chetan is right.

A requried to work is 23 days
A is 30% more efficient than B,that means B requried 30% more time than A
so,30% of A time= 23*30/100=6.9
so time requried for B=23+30% of A= 23+6.9=29.9
now,work per day for (A+B)=1/23+1/29.9 above work as per rule

Had 100:130 confusion too due to misconception of "efficiency". See Physics says efficiency = (work of A/work of B) * 100. But here work is same, so we can use power. So E= (Power of A/Power of B) * 100. As work is same & P=W/T, so E = (time taken by B/time taken by A) * 100=130 So time taken by A:time taken by B :: 130:100.

It's easy.
A work 30% more efficient than B.
A's efficiency = 1/23 word/day.......(1).

Let B's efficiency = x work/day.
Then A's efficiency(A/C to question) = x+x*(30/100) = 13x/10....(2).

From equation 1 & 2 we get x = 10/299.
So B's efficiency = 10/299 work/day.

Now, (A+B) efficiency = 1/23 +10/299 = 23/299 = 1/13 work/day.
So (A+B) will complete 1 work in 13 day(answer).

A=1/23.
A=1.3B.

So B=1/(23*130/100).
B=10/(23*13).

A+B=1/23+1/(10/(23*13)).
So A+B=1/13.

Answer is 13 days.