The Pencil Eraser Cost Problem is given below
Question:
Romila went to a stationary stall and purchased 2 pencils and 2 erasers for Rs 8.
Her friend Sonali saw new variety of pencils and erasers with Romila, and she also bought 4 pencils and 6 erasers for Rs 18.
Find the cost of a pencil and an eraser?
Answer:
Let the cost of a pencil be Rs x and the cost of an eraser be Rs y.
It is given that Romila purchased 2 pencils and 2 erasers for Rs 8.
So, 2x+2y=8
=> x+y=4 ……………. (1)
=> x=4-y …………….. (2)
It is also given that Sonali purchased 4 pencils and 6 erasers for Rs 18.
That is, 4x+6y=18
=> 2x+3y=9 …………. (3)
putting the value of equation (2) into equation (3), we get
2(4-y)+3y=9
=> 8-2y+3y=9
=> 3y-2y=9-8
=> y=1
put the value of y in equation (2),
x=4-y
=> x=4-1
=> x=3
The cost of a pencil is Rs 3 and the cost of an eraser is Rs 1.
Got a question ? 
Leave me a COMMENT AND ILL GET BACK TO YOU!