Reasoning
Stage 5's clue tells us that 150m was left. So the distance left at the start of Stage 4 must have been:
Dist4 = Dist4 + 75 + 150
—————
2
Which simplifies to give Dist4 = 450m.
Stage 3's clue tells us that 450m was one quarter of the remaining distance, so Dist3 = 1,800m.
Stage 2's clue tells us that the distance at the start of Stage 2 was:
Dist2 = Dist2 + 35 + 1800
—————
2
Which simplifies to give Dist2 = 3,670m.
Stage 1's clue tells us that 3,670m was half the overall distance, which means the entire ride was 7,340m.
Double-Checking
Starting with 7,340m:
Stage 1: cycled 3,670m, leaving 3,670m
Stage 2: cycled 1,870m, leaving 1,800m
Stage 3: cycled 1,350m, leaving 450m
Stage 4: cycled 300m, leaving 150m
Stage 5: cycled 150m, leaving 0m
?
Puzzle 6
Hidden in the grid below are three boys names. Starting at any point, trace out the path of a chess knight. The last letter of one name starts the next one. What are the names?
Once you have unscrambled the following countries, the first letters can be anagrammed to make a hidden country. aadnorraehiioptceeegraaaacdgmrsanorwyaaimnoreemny
Reasoning aadnorr = Andorraaehiiopt = Ethiopiaceeegr = Greeceaaaacdgmrs = Madagascaranorwy = Norwayaaimnor = Romaniaeemny = Yemen
a + e + g + m + n + r + y = Germany.
?
Puzzle 8
Many years ago, a cruise liner sank in the middle of the Atlantic Ocean. The castaways luckily landed on a remote desert island.
There was enough food for the 135 people to last four weeks.
Nine days later a rescue ship appeared, unluckily this ship also sank, leaving an additional 36 people stranded on the island to now share the original rationed food.
The food obviously had to be re-rationed, everyone was now on three-quarters of the original ration, so how many days in total would the food last, from the day of the original sinking?
Originally there was enough food for 135 people for 28 days, which totals 3780 rations.
After 9 days, 1215 rations had been eaten.
Therefore there were now 2565 rations left for 171 people, which would last for another 20 days at three-quarter rations per person = (2565 ÷ 3/4) ÷ 171.
Which is 29 days in total from the original sinking.