Q. $A$ is greater than $B$ by $25text{%}$ then by what percentage $B$ is less than $A$ ?

**my approach**:

$A$ is greater than $B$ by $25$% then

$${A-Bover B}times 100=25$$

$$A=B+0.25B=1.25B$$

Now, $B$ is less than $A$ by %

$$frac{A-B}{B}times 100=frac{1.25B-B}{B}times100=25text{%}$$

Is my answer correct? I don’t know where I am wrong.

Help me solve this question. Thanks.

Mathematics Asked by user809080 on December 3, 2021

4 AnswersWorking with percentages is always, always, always a multiplication, never, never, never and addition or a subtraction, like in this case:

```
A = 1.25 * B
B = 1/1.25 * A
= 0.8 * A
```

And 0.8*... means, subtract 20%.

Answered by Dominique on December 3, 2021

There's a problem in your question. In Q you say

$A$ is greater than $B$ by $20%$

but then in your attempt you say

$A$ is greater than $B$ by $25%$.

I will assume the second statement is correct.

I think the best way to think of percentage change is as multiplication by a factor. Then "$A$ is greater than $B$ by $25%$" means $$ A = 1.25B . $$ So (solving for $B$)

$$ B= frac{A}{1.25}= frac{1}{1.25}A = 0.8A = (1-0.2)A $$ so $B$ is $20%$ less than $A$.

For a slightly more abstract argument, see How to get the reverse percentage (not amount of reverse percentage)?

Answered by Ethan Bolker on December 3, 2021

In such questions is most important to clearing which number we are taking as 100%.

When we say $A$ is greater than $B$ by 25% of $B$ then $A=B+Bcdot 0.25$

When we say $A$ is greater than $B$ by 25% of $A$ then $A=B+Acdot 0.25$

Same for reverse.

Answered by zkutch on December 3, 2021

Your answer is not correct. You must take $text{%}$ of B w.r.t. A as follows $$frac{A-B}{A}times 100=frac{1.25B-B}{1.25B}times 100=frac{1}{5}times 100=20text{%}$$

Answered by Harish Chandra Rajpoot on December 3, 2021

1 Asked on November 22, 2020 by david-dong

contest math euclidean geometry geometry power of the point solution verification

2 Asked on November 21, 2020 by aspro

2 Asked on November 21, 2020 by manas-dogra

algorithms arithmetic functions computational mathematics elementary number theory gcd and lcm

1 Asked on November 21, 2020 by xenusi

1 Asked on November 21, 2020 by consider-non-trivial-cases

1 Asked on November 19, 2020 by lena67

1 Asked on November 19, 2020 by nerdy-goat

1 Asked on November 18, 2020

2 Asked on November 17, 2020

decidability diophantine equations elementary number theory reference request

1 Asked on November 17, 2020 by kapur

1 Asked on November 16, 2020 by trevor-frederick

1 Asked on November 15, 2020 by lord-shadow

0 Asked on November 15, 2020 by soham-chatterjee

0 Asked on November 15, 2020 by ali-shadhar

closed form harmonic numbers integration polylogarithm sequences and series

1 Asked on November 14, 2020 by davi-barreira

1 Asked on November 14, 2020 by jcaa

1 Asked on November 13, 2020 by across

2 Asked on November 12, 2020 by vitagor

distribution theory partial differential equations sobolev spaces weak derivatives

0 Asked on November 12, 2020 by rohitt

Get help from others!

Recent Answers

- DMGregory on MouseLook Script “Pops” back to the last value when the script is enabled after being disabled or destroyed
- Justin Markwell on Unity app crashes when using unmodified custom Android manifest (didn’t find class “UnityPlayerActivity”)
- eric_kernfeld on How to test consistency of responses?
- kjetil b halvorsen on How to test consistency of responses?
- Philipp on How do i draw a ray in unity

Recent Questions

- MouseLook Script “Pops” back to the last value when the script is enabled after being disabled or destroyed
- Unity app crashes when using unmodified custom Android manifest (didn’t find class “UnityPlayerActivity”)
- How do i draw a ray in unity
- How to test consistency of responses?
- How can I understand these variograms?

© 2022 AnswerBun.com. All rights reserved.