Find the Jar with contaminated pills | Puzzles for Interview - Interview Preparation PDF Download

Introduction

In this puzzle, you have five jars of pills, and you need to find the jar that contains contaminated pills in just one measurement.

The Challenge

Each pill weighs 10 grams, except for the contaminated pills in one jar, where each pill weighs 9 grams. With the help of a scale, you need to identify which jar has the contaminated pills in just one measurement.

Solution

You can find the contaminated jar by following these steps:

Step 1: Take out one pill from jar 1, two pills from jar 2, three pills from jar 3, four pills from jar 4, and five pills from jar 5.
Step 2: Put all these 15 pills on the scale. The total weight should be 150 grams (15 x 10), but because one jar has contaminated pills, the weight will be less than 150.
Step 3: If the weight is 149 grams, then jar 1 has contaminated pills because there is only one contaminated pill. If the weight is 148 grams, then jar 2 has the contaminated pills. Similarly, if the weight is 147 grams, then jar 3 is the contaminated one, if it's 146 grams, then jar 4 is contaminated, and if it's 145 grams, then jar 5 has contaminated pills.

Conclusion

By following these simple steps, you can easily identify which jar has the contaminated pills. It is essential to be careful while conducting this measurement to ensure accurate results.