You are Here: Home >< Maths

# How do you answer this maths question?

Announcements Posted on
Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. I'm doing some work on direct and inverse proportion and I stumbled on this question which I don't understand. How do you answer it? many thanks

The variable P is inversely proportional to Q^2 i.e. P=k/Q^2

Q is increased by 40%.

What is the percentage change in P in percentage terms?
2. (Original post by choondy1)
I'm doing some work on direct and inverse proportion and I stumbled on this question which I don't understand. How do you answer it? many thanks

The variable P is inversely proportional to Q^2 i.e. P=k/Q^2

Q is increased by 40%.

What is the percentage change in P in percentage terms?
If Q increases by 40%, what does Q^2 increase by? And why am I asking you this?
3. (Original post by SeanFM)
If Q increases by 40%, what does Q^2 increase by? And why am I asking you this?
I assume that you multiply Q by 1.4 so you'll end up with (1.4Q)^2, which is 1.96Q^2. That's as far as I got so far.
4. (Original post by choondy1)
I assume that you multiply Q by 1.4 so you'll end up with (1.4Q)^2, which is 1.96Q^2. That's as far as I got so far.
Well done, that is right So in terms of P from before, what is k/(1.96)Q^2?

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: September 24, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### Who is getting a uni offer this half term?

Find out which unis are hot off the mark here

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams