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Thursday 14 June 2012

Some Mind Boggling IQ Questions

Q. You have 5 jars of pills. Each pill weighs 10 grams, except for contaminated pills contained in one jar, where each pill weighs 9 grams. Given a scale, how could you tell which jar had the contaminated pills in just one measurement?

Solution :

• Follow the steps outlined below:
• Step-1: Mark the jars with numbers 1, 2, 3, 4, and 5.
• Step-2: Take 1 pill from jar 1, take 2 pills from jar 2, take 3 pills from jar 3, take 4 pills from jar 4 and take 5 pills from jar 5.
• Step-3: Put all of the jars on the scale at once and take the measurement.
• Step-4: Now, subtract the measurement from 150 (1*10 + 2*10 + 3*10 + 4*10 + 5*10)
• Step-5: The result will give you the jar number which has the contaminated pills.


Q. One train leaves Los Angeles at 15 MPH heading for New York . Another train leaves from New York at 20mph heading for Los Angeles on the same track. If a bird, flying at 25mph, leaves from Los Angeles at the same time as the train and flies back and forth between the two trains until they collide, how far will the bird have traveled?  
 
Solution :
The distance traveled by the bird can be calculated as:

1. Let's say the distance between LA and NY is d miles.
2. The time before which the trains will collide: d / (15+20) hours.
3. The distance traveled by the bird in that time: (d / 35) * 25 = 5*d/7 miles.

Assumptions made: The bird must follow the line of the track, remain at the same altitude, and the speed must be relative to the ground and not air speed.