Puzzles
Posted by
Ravi Kumar at Monday, November 24, 2008
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Puzzles concept
Puzzles:
Introduction:
Puzzles are dealt in a detailed manner with certain solutions.
Different puzzles are gathered from ShakuntalaDeviâ€™s puzzle
books. Keeping in mind certain puzzles for Infosys some
reasoning problems are also dealt. Puzzle name at the top of
each problem will give a brief idea regarding the mode of
application.
SELECTING A CANDIDATE
For an advertisement of six local posts,twelve persons applied
for the job.Can you tell in how many different ways the
selection can be made?
Solution:
6^12
SET OF BAT AND BALL
When I wanted to buy a bat and ball, the shopkeeper said they
would together cost Rs.3.75.But I did not want to buy a ball.
The shopkeeper said that bat would cost 75paise more than the
ball.What was the cost of bat and the ball?
Soluton:
Given that bat and ball together cost Rs.3.75 = 375paise
Let cost of the ball alone be x.
Given cost of the bat is 75p greater than cost of the ball.
So cost of the bat = x+75
x+x+75 = 375
2x = 375 â€“ 75
2x = 300
x = 150p
Hence cost of the ball = Rs.1.50
=>Cost of the bat = 1.50 + 75 = Rs.2.25
PLAYING CHILDREN
A group of boys and girls are playing.15 boys leave.There remain
2 girls for each boy.Then 45 girls leave.There remain 5 boys for
each girl.How many boys were in the orginal group?
Solution:
Let B and G represent no.of boys and girls in the original group
respectively.
G > 2
B15 > 1
G/B15 = 2/1
i.e., 2 girls are left for 15 boys who are alone.
G45 >1
B15 >5
5 boys are left out when 15 girls are alone.
=>G/B15=2/1 (1)
=>G45/B15 =1/5 (2)
(1) & (2) =>
G = 2B30
5G â€“ 225 = B  15
5 ( 2B â€“ 30 ) = B â€“ 15 + 225
10B = B â€“ 15 + 225 + 150
9B = 360
B = 40
(1)=> G/4015 = 2
G=50 girls.