Question

The total cost of 6 books and 4pencils is rupees 34 and that of 5 books and 5 pencils is rupees 30. The cost of each book and pencil in Rupees respectively is.
Please solve this questtion step by step . Please help me.

Answer 1

Let the cost of one book be xrs
One pencil be y rs
According to que
6x+4y=34......1
5x+5y=30.......2
By elimination method
Multiply 1 with 5 and 2 with 6
30x+20y=170
30x+30y=180
(-) (-) (-)
-10y=-10
Y=1
Since5x+5y=30
5x+5=30
5x=25
X=5
Hence cost of each book is 5 rs and each pencil is 1 rs

Answer 2

let the cost of one book be x and the cost of one pen be y
From the 1st condition,
6x+4y=34
Divide both sides by 2,
3x+2y=17..........1
From the 2nd condition,
5x+5y=30
Divide both side by 5,
x+y=6..........2
Eliminating y,
Multiply Eqn 1 by 1 n Eqn 2 by 2
3x+2y=17
2x+2y=6
_ _ _
x. =5

Put x=5 in Eqn 2
x+y=6
5+y=6
y=6-5
y=1

therefore cost of one book is Rs.5
cost of one pen is Rs.1