Possibly a stupid maths question

Diddums · 2 Nov 2015 at 18:40

Having a bit of a braindead moment here.

This is what I've got:

Maths question. This is exactly how it's worded:

*The total amount of people surveyed is 60*

A survey suggests that introducing water coolers to the building is expected to increase the number of people drinking water. In this survey, 42 people said that they already drink water, and in total 57 said that they would drink water if a water cooler was available. Based on this information, calculate the percentage increase in the likely number of people drinking water when a water cooler is introduced, giving your answer to the nearest whole number.

According to my maths, 42/60 x 100 = 70%, and 57/60 x 100 = 95%.

95% - 70% = 25%.

BUT!

I can't figure out if the percentage should be from the total of 60, or relative to the original number.

Thoughts?

TIA

Dis86 · 2 Nov 2015 at 18:41

Hmm, it's a difficult one tbh. There's a key bit of information missing to get a single definitive answer. You have to make the assumption that all those who do drink water are included in the 57 who would.

adolf hamster · 2 Nov 2015 at 18:48

It would make the most sense to express it as a % of the total, if you werent given the total it would be better to express as a % of the current drinkers.

Socaddict · 2 Nov 2015 at 18:48

percentage increase in likely drinkers.

I'd work it out as the increase from 42 to 57:

(57/42)-1 = 0.357

Therefore 36% increase.

The nearest whole number bit suggests this way too.

Greebo · 2 Nov 2015 at 18:50

original number so its 36%

Kenai · 2 Nov 2015 at 18:51

If they've asked for percentage increase, I'd be answering 36%

Elixir · 2 Nov 2015 at 18:51

I'd do the relative % increase as above.

dirtychinchilla · 2 Nov 2015 at 19:10

Socaddict said:
percentage increase in likely drinkers.

I'd work it out as the increase from 42 to 57:

(57/42)-1 = 0.357

Therefore 36% increase.

The nearest whole number bit suggests this way too.

FoxEye · 2 Nov 2015 at 19:28

The increase is 15. (57 - 42).

Therefore the % increase is 15/42 (0.3571)

So the %increase is ~36%.

I know you guys have already arrived at the same result, but (57/42)-1 is just messy!

ZeroG · 2 Nov 2015 at 20:15

But what if the water is in tea, does that count

glenimp617 · 2 Nov 2015 at 20:21

Every single maths question on the internet has the same technique to find the answer

BODMAS

aardvark · 2 Nov 2015 at 20:23

Socaddict said:
percentage increase in likely drinkers.

I'd work it out as the increase from 42 to 57:

(57/42)-1 = 0.357

Therefore 36% increase.

The nearest whole number bit suggests this way too.

this

D3K · 2 Nov 2015 at 20:32

glen8 said:
Every single maths question on the internet has the same technique to find the answer

BODMAS

Did you get expelled before your GCSEs?

D.P. · 2 Nov 2015 at 20:42

It clearly says percentage increase, not increase in percentages.

Firestar_3x · 2 Nov 2015 at 21:07

Someone is doing MU123 TMA-01

Diddums · 2 Nov 2015 at 21:15

Shush you

Diddums · 2 Nov 2015 at 21:16

Thanks for the input all, it's greatly appreciated!

estebanrey · 2 Nov 2015 at 23:59

There would be a 36% increase in the number of people drinking water, and a 25 percentage point increase in the drinking water participation rate.

Diddums · 3 Nov 2015 at 18:05

Hello, me again

Got another one which is confusing the hell out of me but I think I'm overthinking it.

Problem: Gabriella is planning a trip abroad. Her friend tells her about a formula that she can use to estimate the extra (hidden) costs E, in pounds, involved in using a budget airline rather a standard airline. The formula is
E = 32l + 3h
where l is the number of pieces of checked luggage that she wishes to take, and h is the number of flying hours for the round trip.
(i) Gabriella plans to fly from Gatwick to Rome, a round trip involving 2 hours 25 minutes total flying time, and she would like to take one piece of checked luggage. Use the formula to find the extra cost involved in using a budget airline for such a trip.
(ii) Gabriella finds return flights advertised from Gatwick to Rome costing £88 from a budget airline and £126 from a standard airline. Assuming that the formula holds, explain why she would be better off choosing the standard airline.

I've worked out (i) as £34.42 which means that for (ii) it still works out cheaper for the budget airline, but only marginally. I want to say "use the standard airline as the price difference is negligible" but I'm not 100% sure :confused:

Help!

Kenai · 3 Nov 2015 at 18:13

You've worked out i wrong.

32x1 + 3x2.42 isn't 34.