## Welcome to H3 Maths

Blog Support for Growing Mathematicians

### When difference = a big difference

August26

Difference can make a big difference, especially when you take into account the daily cost of putting petrol in your family car. Venezuela is the cheapest country to buy petrol in at just 8p a litre, while residents of neighbouring nation Columbia pay more than 40 times as much for their fuel. After Venezuela, Egypt (9p a litre), Saudi Arabia (10p a litre), Qatar (12p a litre) and Bahrain (15p a litre) are the cheapest countries to but petrol in.

By contrast, Norway was found to be the most expensive country to fill up in – with petrol costing an astonishing 1.64p a litre in the Scandinavian state. Here is an interesting graph of some petrol prices – but, of course, the graph could be done quite differently to highlight the real contrast in prices. You might like to work out a better way to display this data?
Is there really a world shortage of petrol. No! Check out this TED talk given by Richard Sears.

by posted under Uncategorized | Comments Off on When difference = a big difference

#### Post Support

The graph on the left (Coronavirus) is for a time period of 30 days, while the one on the right (SARS) is for 8 months! Very poor graphical comparison and hardly relevant, unless it is attempting to downplay the seriousness of the coronavirus?

10 x 9 x 8 + (7 + 6) x 5 x 4 x (3 + 2) x 1 = 2020

NCEA Level 2 Algebra Problem. Using the information given, the shaded area = 9, that is:
y(y-8) = 9 –> y.y – 8y – 9 =0
–> (y-9)(y+1) = 0, therefore y = 9 (can’t have a distance of – 1 for the other solution for y)
Using the top and bottom of the rectangle,
x = (y-8)(y+2) = (9-8)(9+2) = 11
but, the left side = (x-4) = 11-4 = 7, but rhs = y+? = 9+?, which is greater than the value of the opp. side??
[I think that the left had side was a mistake and should have read (x+4)?]