Answers

2014-04-20T16:31:43+05:30
Let x,y and z represent no. of pens with mohit,ram and sam respectively
so
x+y=20
z-y=7..(1)
x-z=2...(2)
therefore add (1) and (2)
x-y=9
x+y=20
-----------------
2x=29
x=29/2
y=11/2
 there can't be 11/2 pens please check ur question

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yes u are right
i edited
Are u sure your answer has no mistake
yes
Then question will wrong
2014-04-21T15:23:13+05:30
Approx answer Will be 5 or 6 pens.. cos the question has some mistake.. 
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