Aptitude - Puzzle

Hi all I am amod from NSS COLLEGE OF ENGG PALAKKAD  .i attended infosys test.

1.i play a game with my friend and we decide to exchange a rupee for each one loses.if I gained 3 rupee in the end and my friend won three times then how many games we played in all.

A)    9 .i gained 3rs means I won three games more than my friend

He won three times means I must win 6 times to gain 3rs

Therefor total no of games=6+3=9

   2.series problem

a> 3125,256,27,_,1

b>3,10,7,8,_12,9,16

ans)a:4

      b:11

approach a:1^1,2^2,3^3,4^4,5^5…

b:1st element  +last element=19

2^nd+2ndlast=19……….

Therefore 8+11=19

3.two watches r set together one was faster by 1min per hr.other was slower by 2min per hr.after sometime the two watches had 1 hr difference .after how many hrs they showed one hr diff?

Ans)20 hrs

In 1 hr net diff=1+2=3min

Therefore for 1hr diff i.e for 60min diff to happen total no of hrs=60/3=20hrs.

4. A s/f engg starts from home at 3pm for evening walk. He walked with a speed of 4km/hr on level grnd, then with a speed of 3km/hr uphill and then downhill at a speed of 6kmph to the level grnd and then at a speed of 4kmph to the home at 9pm. what is one way distance?

Ans) 12 .soln : x/4+y/3+y6+x/4=9hr

x+y=12.

5.same old thief problem .half diamonds+2,2^nd thief half of the remaining+2,3^rd and 4^th thief…only 1 diamond left u can get it in previous papers.

Ans)76

6.there is a tank with 3 pipes .one is  for draining and the other two for filling.one of the pipe can fill the tank in 7 and half minutes and the other in 6 min.the draining pipe can drain water from the whole tank in 8 in.will the tank ever be filled completely? If yes how?

Ans)yes. I think the ans is 30 min.

Soln.work done by pipe A in unit time=1/6

Work done by pipe B in unit time=7+1/2=2/15

Pipe C (draining pipe)=1/8

So the whole tank will b filled in=1/6+2/15-1/8

=1/30

Therefore 30 min.

7.same problem x,c,v,had 20 rs.they ha to buy 20 stuff from it.one was for 4rs.other was for .25rs next one for .5rs ( theygave amnt in terms of cents and pennies so study the relation).u can find this qn in previous paper.

3 variables but two equations.

8.same old gems problem

A jewller makes a windw displayhe has 7 gems of which he needs to display 6..

U can find this in previous paper

9. four friends r chatting in a room one by one entering into the kitchen room and they r taking the samosas and returning.at the end no samosa .one among the four had eaten it.only one is telling the truth and remaining r lying type of qn u can find in most papers

10.this was a lengthy qn I had seen it in previous paper but didn’t know the soln

Four persons sitting around the table.in front of each of them r cards. two yellow,red green ,blue .both sides of the card r painted.no one knows the card colour of the bottom face.