Since we're after three numbers that multiply together, a good place to start is the cube root of 1,287, which is 10.88 (2 dp).
We quickly find that the numbers must be 9, 11 and 13.
Which is heavier, a kilo of feathers or...
...a kilo of steel?
Hint: This is a Gotcha.
Answer: They weigh the same.
I have a drawer full of socks.
There are 5 socks of each colour, red and green, evenly mixed. In the morning, when it is very dark, I need to pull out a pair of socks of the same colour.
How many must I pull out of the drawer to ensure that I have at least one pair of matching socks?
Hint: I'm after a pair of any colour.
Answer: Three socks.