February 2014 Logic & Maths Problems Solutions

1. The water level of the pool will fall. The cannonball is much denser than the water. Let the cannonball have a volume of x litre. Assume the cannonball is ten times as dense as the water. Its mass will therefore be 10x kg. When the cannonball is placed in the boat, the boat settles by an amount which displaces 10 kg of water or 10x litres of water. However, when the cannonball is taken out of the boat and placed directly in the water, it only displaces its own VOLUME of water or x litres. This will have the same effect on the water level of the pool as taking 9x litres out.
2. Treble = 18, double = 4, single = 13
3. 2519 prisoners
4. The rule is: double the first number then take away 8. The answer is therefore 20
5. 13 triangles
6. 30 picknickers
7. a. 54m b. 6th c. 11th d. 22 times
8. Direction A (The doors must be on the other side or kerb side, & they drive on the right)
9. $20
10. (a) Keep Still (b) Call a Cab

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: