Four Digit Number
The first digit is one third of the second digit
The third digit is the sum of the first two digits
The fourth digit is three times the second digit
What is the number?
Two trains run between stations at A and B
The first train runs from A to B at 85mph
The second train runs from B to A at 105mph
How far apart will the trains be 30 minutes before they pass each other?
You have 12 marbles
The marbles are all the same size, shape and colour – they look identical
One marble is heavier in weight than the others
How can you work out which marble is the heavier one, using only a balance scale, if you can only use the balance scale 3 times to work out the answer?