Christian Lawson-Perfect

Christian Lawson-Perfect on Find the equation of a line through two points - positive gradient 8 years, 5 months ago

Gave some feedback: Ready to use

Christian Lawson-Perfect on Find the equation of a line through two points - positive gradient 8 years, 5 months ago

Saved a checkpoint:

Made sure neither of the points lies on the $y$-axis.

Split $a$ into two parts, since you need to work out the gradient before you find the $y$ intercept.

Reworded some of the advice a bit.

Christian Lawson-Perfect on Use speed and distance to calculate time 8 years, 5 months ago

Gave some feedback: Ready to use

Christian Lawson-Perfect on Use speed and distance to calculate time 8 years, 5 months ago

Saved a checkpoint:

You'd never be told the speed of a greyhound without knowing its time, but you might know how fast the rabbit goes, so I've changed to that.

Christian Lawson-Perfect on Exponential increase 8 years, 5 months ago

Gave some feedback: Ready to use

Christian Lawson-Perfect on Exponential increase 8 years, 5 months ago

Saved a checkpoint:

Used the currency function to make sure prices are displayed properly (two d.p. when not a whole number of pounds)

Good question!

Christian Lawson-Perfect on Identify independent events 8 years, 5 months ago

Gave some feedback: Should not be used

Christian Lawson-Perfect on Identify independent events 8 years, 5 months ago

Saved a checkpoint:

The options don't explicitly list two events! They're all of the form "event A given event B" - B isn't an event you can put a probability on, because it's already happened.

I can't find a quick way of rewording this so it makes sense, so I'm marking as shouldn't use.

Christian Lawson-Perfect on Lowest common multiples 8 years, 5 months ago

Gave some feedback: Ready to use

Christian Lawson-Perfect on Lowest common multiples 8 years, 5 months ago

Saved a checkpoint:

The naive approach is to write out the times tables for each number, so I've put that in the advice. 

I've reworded "$a$ and $b$ are coprime" to "$a$ and $b$ have no factors in common", which is hopefully a bit easier to agree with if you're not good at spotting primes.