self Maths Puzzle

We have two red, two green and two yellow balls.

For each color, one ball is heavy and the other is light.

All heavy balls weigh the same. All light balls weigh the same.

How many weighings on a beam balance are necessary to identify the three heavy balls?

Read Solution (Total 1)

min. 3 weighing
ist weighin between 2 same colour ball, and left with other colour of balls.
12 years agoHelpfull: Yes(0) No(1)

self Other Question

A pool has four taps.

The first tap takes two days to fill the pool, the second tap three days, the third four days and the last one only 6 hours.

How long will it take to fill the pool using all 4 taps at once?
Two trains are 200 km apart, and travelling towards each other at 50 km/hour each.

From one train a fly takes off, flying straight above the rails to the other train at the speed of 75 km/hour, bounces off it and flies back to the first train.

This is repeated till the trains crash together and the fly is smashed (Headline: Fly Dies in Freak Train Crash)

What distance is the fly able to fly until its meet its tragic end?

Note: there is a complicated and an easy way to solve this one.