### Rule of Three

If it takes four men one day to build a wall, how long does it take 60,000 men to build a similar wall?

### Square Pegs

Which is a better fit, a square peg in a round hole or a round peg in a square hole?

### How Big?

If the sides of the triangle in the diagram are 3, 4 and 5, what is the area of the shaded square?

# Cereal Mix

##### Age 11 to 14Challenge Level

A farmer is supplying a mix of seeds, nuts and dried apricots to a manufacturer of crunchy cereal bars.

The ingredients cost:
• dried apricots $£7$ per kg

• nuts $£6$ per kg

• seeds $£4$ per kg

He has been asked to supply a mix which costs $£5$ per kg.

What combination of ingredients could he supply?

Is there a relationship between the amounts of each ingredient that he could supply?