Puzzle 21

During a recent trip to Scotland, I filled my petrol tank to the top, a total of 10 gallons.

I travelled at 60 mph up the motorway and I knew that I could average 40 miles per gallon.

However, the moment I started, my petrol tank developed a leak and four hours later I ground to a halt having run out of petrol.

How much petrol had I lost through the leak?

Puzzle 22

The BrainBashers safe has a rather unusual control panel.

In order to open the safe you have to press every single button once only, in the correct sequence, ending on the button marked E.

Each button clearly states which button to press next, for example, 2U means move up 2 buttons and 3R means move right 3 buttons.

 6D 6D 1R 1R 1R 1R 1D 2D 1D 1U 2L 1R 2D 2L 2U 4R 1U 3R 2D 5L 2L 1R 3U 1U 2D E 2D 3L 3U 1L 1U 2L 2D 2L 1L 1R 3R 1U 3U 2U 1D 2U 1U 2R 1U 5U 2L 1R 2U

Puzzle 23

Below you can find 10 words which have had their beginnings and endings removed. In each case, the same two letters can be found at the beginning and the end. For example REspiRE.

..QUI..
..YLI..
..GIB..
..SUL..
..LIV..
..IFI..
..RMI..
..ALG..
..GRA..
..STO..

Puzzle 24

Complete this grid with the digits 1 to 6 to make the sum correct.

Perform each mathematical operation in the order shown, from left to right, e.g. 1 + 2 x 3 is treated as (1 + 2) x 3 = 9.

Note: there is no ÷ 1, and at no point is a decimal or fraction used.