Many years ago, a cruise liner sank in the middle of the Atlantic Ocean. The survivors 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?
[Ref: ZJLO] © Kevin Stone
Hint: How many rations did they start with?
Answer: 29 days.
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.
I recently travelled from my home town to a distant music concert, on a pedal tricycle of all things! My wonderful, three wheeled tricycle.
I knew that the epic 2,345 mile trip would wreak havoc on the tyres, but luckily I took along 4 spares!
Instead of waiting for any single tyre to fail, I decided that I would rotate the tyres evenly, making sure that by the end of the trip all seven tyres had travelled exactly the same distance.
What was the distance that each tyre travelled?
[Ref: ZDFX] © Kevin Stone
Hint: How many tyre miles were travelled?
Answer: 1,005 miles.
A total of 2,345 miles were travelled and at any one time, three tyres were on the tricycle.
Therefore 3 x 2,345 = 7,035 tyre miles were travelled, which was shared equally by the 7 tyres.
And 7,035 ÷7 = 1,005.
Can you find a number such that...
...its double is fourteen more than its quarter?
[Ref: ZZMR] © Kevin Stone
Hint: The number is less than 20.
We need a number such that:
2 x Number = 14 + 1 x Number
Multiply throughout by 4 to give:
8 x Number = 56 + Number
7 x Number = 56
So Number = 8.
Exactly how many minutes is it before eight o'clock if...
...40 minutes ago, it was three times as many minutes past four o'clock?
[Ref: ZOIC] © Kevin Stone
Hint: How many minutes are between the times?
Answer: 50 minutes.
Between four o'clock and eight o'clock we have 240 minutes.
In these 240 minutes we have 4 lots of the unknown time (t) and 40 minutes.
Therefore 240 = 4 x t + 40.
Therefore t = 50 minutes.