FORTNIGHT'S PUZZLE 5

PUZZLE 5: 30th November-6th December (to be e-mailed by the 7th December)
POSTED BY IES CAMPANAR

THE AIRCRAFT
A light aircraft has just flown 400 kilometres. The aircraft covered the first 100 kms at a speed of 150 kph, the next 100 at 300 kph, the following 100 at 450 kph, and the last 100 at 600 kph.Can you figure out the average speed of the aircraft on its 400 kilometres journey?

SOLUTION
t = e/v (t = time, e = space, v = velocity)t1 = 100/150 = 2/3t2 = 100/300 = 1/3t3 = 100/450 = 2/9t4 = 100/600 = 1/6T = 2/3 + 1/3 + 2/9 + 1/6 = 25/18v = E/ T = 400 : (25/18) = 288 kph

THE GOODE FAMILY: Goodes gone wild

THE GOODE FAMILY: Pleatherheads 2

THE GOODE FAMILY: Pleatherheads 1

THE GOODE FAMILY: PILOT 2

FORTNIGHT'S PUZZLE 4

PUZZLE 4: 16th-22nd November (to be e-mailed by the 23rd November)


POSTED BY IES CAMPANAR

A FOOTBALL


A polyhedron with the shape of a football has 32 sides: 20 of them are regular hexagons and 12 are regular pentagons, as you can clearly see in the picture above.How many vertices and edges does this solid have?



SOLUTION


The football has as many vertices as the pentagons have: 12x5=60. As for the number of edges, which are counted twice, there are as many as the edges of all the polygons: (20x6 + 12x5)/2 = 180/2 = 90.

THE GOODE FAMILY: PILOT 1

FORTNIGHT'S PUZZLE 3

PUZZLE 3: 2nd-8th November (to be e-mailed by the 9th November)
POSTED BY IES CAMPANAR

CHESS
Malcom and Cynthia were playing chess. They each played five games. Each of them won the same number of games and there were no draws. How is this possible?

SOLUTION
They were playing with different people