Arun Sharma Solutions for Chapter: Logical Reasoning Questions, Exercise 3: Level of Difficulty (LOD)-III

Each of the four friends - Amitesh, Bani, Chayaa and Devesh - got admission in different engineer- ing colleges of Lucknow among Bansal, BBD, Ram Swaroop and BIT, not necessarily in the same order. Also, the four had different surnames among Joshi, Rao, Arora and Trivedi, in no particular or- der. Each of them was good at exactly one subject area among Maths, Physics and Chemistry. The one who got admission at BBD was named Arora and he/she was not good at Chemistry, Devesh got admission at Ram Swaroop, and he was not Joshi. Amitesh Rao who got admission at BIT, was good at Maths. Chayaa was good at Chemistry

Which of the following is the correct combination of Bani's college and surname?

There are fifteen boxes and each box contains seven gemstones. Each gemstone in one of the boxes weighs $22$ grams and each gemstone in the rest of the fourteen boxes weighs $20$ grams each. What is the minimum number of weighings required to identify the box containing $22$-gram gemstones using an electronic weighing machine?