Question

Reena has. Pens and pencils which together are 40 in number. If she has 5 more pencils and 5 less pens,then number of pencils would become 4 times the number of pens . Find original number of pens and pencils.

Answer 1

Reena has pens and pencils which together are 40 in number. If she has five more pencils and five less pens, then the number of pencils would become four times the number of pens. Find the original number of pens and pencils. Answer in detail.

Solution :
Number of Pens and Pencils = 40
Let the number of Pens = x
and let Number of Pencils = y
therefore ,
x + y = 40
=> y = 40 - x ............................. (1)
According to Question ,
y + 5 = 4 ( x - 5 )
y +5 = 4*x - 4*5
y + 5 = 4x - 20
y = 4x -20 -5
y = 4x - 25 ...................................(2)
from 1 and 2 , we get
4x - 25 = 40 - x
4x = 40 - x + 25
4x + x = 40 + 25
5x = 65
x = 65/5
x = 13

Therefore Number of Pens = 13
Substitute the value of x in 1 , we get
y = 40 - x
y = 40 - 13
y = 27

Therefore Number of Pencils = 27

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