Ben drove from Town A to Town B, a distance of \( 60 \) km, at an average speed of \( 80 \) km/h. He cycled back at an average speed of \( 20 \) km/h. Find his average speed for the whole journey.
Note that it is not \( \textit{50} \) km/h.

A box containing 720 oranges was bought for $180. The cost could be written as:

A carpet measuring 2 m by 16 m is to be paved. The paving tiles cost $36/m² and the installer charges $12/m² to lay the tiles.   How much will it cost to pave the parget to the nearest $50?

A tank of capacity 50 kL is to be filled by a hose whose flow rate is 150 L/min. If the tap is turned on at 10 am,   when will the tank be filled?

The rate of 1 teacher per 14 students is used to staff a school.   How many teachers will be required for a school with 745 students?

The land is valued at $50/m².   How much land could be bought for $70000?

Express ‘A space of 600 m² was cleaned in 30 minutes’ using a rate in simplest form.

Express ‘A balloon of volume 4800 m³ was inflated in 60 seconds’ using a rate in simplest form.

Express ‘The cost of 20 L of fuel was \(\$29\)’ using a rate in simplest form.

The angles of a quadrilateral are in the ratio \( 2:3:4:6 \).

Find the difference in magnitude between the smallest and largest angles.