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In a school there are two sections A and B. When a few students from 11 Nov 2019, 02:34
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C
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51% (03:16) correct 49% (03:19) wrong based on 229 sessions

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In a school there are two sections A and B. When a few students from section B took transfer to section A the strength of section A increased by 22.5% and strength of B decreased by 30%. Now, what percentage of students in section A should be given a transfer to section B such that section A and section B have the same strengths?


A. \(\frac{100}{7}\)%

B. 20%

C. \(\frac{200}{7}\)%

D. 40%

E. \(\frac{300}{7}\)%



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C
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In a school there are two sections A and B. When a few students from 11 Nov 2019, 03:11
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let students in class B = 100
after decrease = 70 ; so 30 were transfered
Section A = x
x+30 = 1.225x
x= ~ 133
new strength = 133+30 ; 163
to have equal strength 163-70 ; 93 ~ 46 students have to be tranfered to B
so 46/163 ; ~ 28%
IMO C


Bunuel
In a school there are two sections A and B. When a few students from section B took transfer to section A the strength of section A increased by 22.5% and strength of B decreased by 30%. Now, what percentage of students in section A should be given a transfer to section B such that section A and section B have the same strengths?


A. \(\frac{100}{7}\)%

B. 20%

C. \(\frac{200}{7}\)%

D. 40%

E. \(\frac{300}{7}\)%



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In a school there are two sections A and B. When a few students from 12 Nov 2019, 02:04
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Hi,
IMO C.

Let B had 100 students and 30 were transferred to A.
A’s new strength =A’ =1.225A
Change = 30 = 0.225A,
A= 400/3
A’ = 400/3 + 30 = 490/3
Let x students need to be transferred from A to B to get them equal.
490/3 - x = 70+x
x=140/3
In percentage of A = (140/3) / (490/3) = 28% = 200/7
C

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In a school there are two sections A and B. When a few students from 24 Nov 2019, 22:05
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Solution


Given:
    • In a school there are two sections A and B.
    • When a few students from section B took transfer to section A the strength of section A increased by 22.5% and strength of B decreased by 30%

To find:
    • Now, what percentage of students in section A should be given a transfer to section B such that section A and section B have the same strengths

Approach and Working Out:
    • Let the strength of sections A and B be A and B respectively
    • If x students take transfer, then the new strengths will be A + x and B - x

Now, we are given that
    • A + x = 1.225A, and
    • B – x = 0.7B
    • Solving two equations, we get, \(A = \frac{4B}{3}\)
      o Implies, \(1.225A = \frac{49A}{40} = \frac{49B}{30}\), and
      o \(0.7B = \frac{7B}{10}\)

Again, if y students are transferred from the new strengths A to B then sections A and B will have equal strength
    • \(\frac{49B}{30} – y = \frac{7B}{10} + y\)
    o Implies, \(y = \frac{7B}{15}\)

Thus, percentage of students to be transferred = \(\frac{7B}{15}/\frac{49B}{30} = \frac{200}{7}%\)

Hence, the correct answer is Option C.

Answer: C
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In a school there are two sections A and B. When a few students from 07 Dec 2019, 04:27
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It took some time for me to understand this. But here goes..

same no of students have been removed from B and added to A, yet different percentage, so find the relationship.

30% of B = 22.5% of A
which gives, A = (4/3)B

With this, now i can easily frame a number.. Say
A
400 -> 22.5% increase -> 490
B
300 -> 30% dec -> 210

Difference has to be divided by 2 ( since we want them to be the same ) so, 280/2 = 140.

140/490 = 0.28 hence a 28%
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In a school there are two sections A and B. When a few students from 01 Mar 2020, 02:57
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Bunuel
In a school there are two sections A and B. When a few students from section B took transfer to section A the strength of section A increased by 22.5% and strength of B decreased by 30%. Now, what percentage of students in section A should be given a transfer to section B such that section A and section B have the same strengths?


A. \(\frac{100}{7}\)%

B. 20%

C. \(\frac{200}{7}\)%

D. 40%

E. \(\frac{300}{7}\)%


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Let A and B be the initial number of students.
After the transfer of x: A+x = 1.225 A = 49/40 A. Similarly, we have new B = 7/10 B.
Now x = 0.225 A = 0.3 B. So 225A=300B or 3A=4B. A= 3/4B. So new B = 7/10*3/4*A = 21/40 A.

Given y students are transferred another time:

49/40A - y = 21/40A + y
2y = (49-21)/40 A = 28/40A
y = 14/40A = 7/20 A.

So the ratio of student regarding new A is (7/20A)/(49/40A) = (7*40)/(20*49) = (1*2)/(7*1) = 2/7 or (200/7)% of new A.

IMO C.
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In a school there are two sections A and B. When a few students from 01 Sep 2022, 04:50
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Bunuel
In a school there are two sections A and B. When a few students from section B took transfer to section A the strength of section A increased by 22.5% and strength of B decreased by 30%. Now, what percentage of students in section A should be given a transfer to section B such that section A and section B have the same strengths?


A. \(\frac{100}{7}\)%

B. 20%

C. \(\frac{200}{7}\)%

D. 40%

E. \(\frac{300}{7}\)%



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Poorly worded question.

The word "strength" lacks a clear definition.

Could just as easily and reasonably be interpreted as being percentage of total rather than absolute number, which interpretation would only be discarded after working through most of the calculation.

If "number" is the intended meaning of "strength", just say so, it ain't hard.

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In a school there are two sections A and B. When a few students from 23 Jul 2024, 09:59
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Inflow in A=22.5%
Lets take this in fraction
225/1000=9/40
Lets assume strength of A be 40,so 9 students addesd,hence new strength =49
Similarly for B
30% gone,that means let b be 30,9 students gone,strength of B now is 21
To make both equal,
49-21/2= 14
In percent=14/49*100=200/7%.

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In a school there are two sections A and B. When a few students from 24 Jul 2024, 07:29
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­One way to solve this:


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