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Question
Reena has pens and pencils which together are 40 in number. If she has 5 more pencils and
5 less pens, then the number of pencils would become 4 times the number of pens. Find the
original number of pens and pencils.
Solution
Let the number of pens be x and that of pencil be y. then,
x + y = 40 ....(i)
(y + 5) = 4(x - 5)
=> y + 5 = 4x - 20
=> 5 + 20 = 4x - y
=> 4x - y = 25 ....(ii)
Adding equation (i) and equation (ii), we get
x + 4x = 40 + 25
=> 5x = 65
`=> x = 65/5 = 13`
Puttign x = 13 in equation (i) we get
13 + y = 40
=> y = 40 - 13 - 27
Hence, Reena has13 pens 27 pencils.
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