Reasoning
If we convert the question to algebra, we have:
((n^2 + 4) x 2 − 3) x 4 − n = 20
Expanding the brackets and simplifying gives:
(2n^2 + 8 − 3) x 4 − n = 20
(2n^2 + 5) x 4 − n = 20
8n^2 + 20 − n = 20
8n^2 − n = 0 (*)
8n − 1 = 0
8n = 1
n = 1/8
In the equation marked (*) zero is also a potential solution, but as the question tells us that we "Start with a number larger than 0" we know that n can't be 0, and therefore we can safely divide by n.
A farmer buys chicken feed for 47c per tonne, pig feed for $1.23 per tonne and cattle feed for $1.44 per tonne. The feed can only be purchased by the tonne, and part tonnes aren't sold.
How much of each would they have if they bought 100 tonnes for $100?
The map below shows the street locations of a city. Position three police officers such that the entire length of every street can be seen by at least one officer.
