# TCS Quantitative Aptitude Questions

1. My flight takes of at 2am from a place at 18N 10E and landed 10 Hrs later at a place with coordinates 36N70W. What is the local time when my plane landed.
a) 6:00 am b) 6:40am c)7:40 d)7:00 e)8:00
2.in 80 coins one coin is counterfiet what is minimum number of weighings to find out counterfiet coin ?
3.Three men goes to a hotel to stay ,the clerk says \$30 per room/day so all the three plans to stay in one room so each pays \$10.After some time the clerk realizes that he made a mistake of collecting \$30 but the room cost only \$25,there fore he decides to return \$5 to them so he calls the roomboy and gives him \$5 asking him to return.The roomboy keeps \$2 with him and he returns only \$3(\$1 for each).Now Totally all have paid \$9 each(\$27)+rommboy \$2 which is equal to \$27.where did \$1 go,who has made the mistake?
This question is related to TCS Interview

#### gans0008 Profile Answers by gans0008

• May 10th, 2006

1) ans: 7.40a.m If it is 2.00 a.m at 18N 10E, then it is 10.40 p.m at 36N 70W. It is because there is a difference of 80 degrees between the two coordinates. Each degree is 4 min, so it comes to 5 hrs 20 min.This is to be subtracted as he is travelling from east to west but the earth moves from west to east.Now, since he has travelled for 10 hrs, add it to 10.40 p.m.

#### imran404 Profile Answers by imran404

• May 11th, 2006

3)  \$30 (Pay by men ) - \$3 (return by roomboy) = \$27

\$27 - \$2 (roomboy keeps with him) = \$25(actual rent)

so there is mistake made by person who write the question

#### arvind singh

• Jun 20th, 2006

To find the counterfiet coin from a group of 80 coins.A minimum of 5 and a maximum of 6 weighings are recquired.                                                     The  chart below illustrates the process.                                                    1>first weighing,40 lighter coins are eliminated.                               2>second weighing the number reduces to 20,which include the countertfiet coin.                                                                                                       3>3.rd weighing other 10 R eliminated.similarly the 4th.                              In the 5th weighing  ,when 2 coins each are placed oneither sides,and if the coins R balanced then the FIFTH COIN is the conterfiet,and if the coins R not balanced then a 6th set of weighing is recquired,which ultimately gives the counterfiet coin.

#### dbera100 Profile Answers by dbera100

• Jan 16th, 2007

The answer is 6:40 AM. Not 7:40 AM

• Sep 30th, 2007

2ed one is 5 chances,,,,,,,,,,,,

#### avin2v2 Profile Answers by avin2v2

• Jul 23rd, 2008

3
since in 2 coins only 1 weighing is required 3 also 1 if 2 coins r identical then third coin is defective or else one of the 2 is defective 4,5,6,7,8 needs 1 test 9 requires 2 tests 27 requires 3 tests 81 requires 4 tests since 80 coins r used only 3 tests r enough
3^1 ...1
3^2....2
3^3...3
since 81lies before 3^4   answer is 3

#### Murugesan_s Profile Answers by Murugesan_s

• Jan 27th, 2010

If it is east to west we should add the degrees and convert that to min. then should subtract with the total hrs given. If it is west to east do it inverse manner.

In this problem 70+10=80;80*4 min=320 min=5 hr 20 min
then total hrs given=10 hrs=>10 hr-5 hr 20 min=6 hr 40 min

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