**Self-assessment questions **

Are these relationships transitive?

(a) ‘is earlier than’ applied to times of the day; and

(b) ‘is half of’ applied to lengths.

(a) in millimetres;

(b) in centimetres;

(c) in decimetres; and

(d) in metres.

(a) An elephant has a mass of about 7000 kg.

(b) A standard domestic bath filled to the brim contains about 40 litres of water.

(c) Yesterday I put exactly 20 litres of petrol in the tank of my car.

(d) A normal cup of coffee is about 2 decilitres.

(e) It takes me about a week to complete a walk of 1000 km.

(f) An envelope containing 8 sheets of standard A4 photocopier paper does not

exceeds 60 g in mass.