The local CD shop operates an unusual discount policy. The discount on the next purchase is worked out on the current purchase in the following way: for every whole pound spent you get 0.5% discount on the next purchase. For example, if you purchased £8.99 on the first purchase, you would then get a 4% discount on the next purchase and so on. You can make as many purchases as necessary.
You need to buy 7 CDs, costing, £11.50, £12.00, £12.00, £12.50, £13.00, £13.00 and £14.50 - what is the cheapest method of buying them?
Answer: Purchase 1: £11.50, £12.00, £12.00, £12.50 = £48.00 (which gives a 24% discount on the next purchase). Purchase 2: £13.00, £13.00, £14.50 = £40.50 minus 24% discount = £30.78. For a total cost of £78.78.
Traffic was bad going to work this morning. I only managed to average 30 mph.
How fast must I go home tonight, along the same route, to average 60 mph for the entire round trip?
Direct Link: www.brainbashers.com?ZNID
Hint: It doesn't matter what the distance is, so try a random distance.
Answer: This cannot be done.
It does not matter how far the trip is, let's assume that it is random distance, say 60 miles, and remembering that Time = Distance ÷ Speed.
The morning trip took 60 miles ÷ 30 mph = 2 hours.
To average the required 60 mph, we would have to travel the total distance (of 120 miles) in 2 hours. However, we've already used all of the two hours for the morning trip!
Choosing any random distance would also show that it can't be done.
The initial letters of the words are spelling BrainBashers.
What comes next in this sequence:
boron carbon nitrogen oxygen
Direct Link: www.brainbashers.com?ZTXL
Hint: The first in the list would be Hydrogen.
These are the elements in atomic number order.