Question

A boy buys 18 sharpeners (brown or white) for rs. 100. For every white sharpener, he pays one rupee more than the brown sharpener. What is the cost of white sharpener & how much did he buy?

Answer 1

Answer:

let the brown sharpener be x.

and the white sharpener be rs. x+1

then,

x+x+1=18

2x=18-1

2x=17

x=17/2

now,

brown sharpener be x=17/2 or 8.5rs.

white sharpener be x+1=19/2 or 9.5rs.

proof....

x+x+1=18

8.5+9.5=18

18=18

hence proved.....

A boy buy white sharpener at rs.9.5

Answer 2

Answer:

Step-by-step explanation:

Total sharpeners purchased

Let the number of white sharpeners be x

So the number of brown sharpeners = 18-x

Let the cost of brown sharpener = z

So the cost of white sharpener = z+1

Total cost = 100

x(z+1) + (18-x)(z) = 100

xz + x + 18z-xz = 100

18z + x =100

18z = 100-x

Now as the value of x needs to be 18(total sharpeners)

And the multiple of 18 close to 100 is 90

So if x = 10

18z = 100-10

18z = 90

z= 5

The cost of white sharpeners shall be = z + 1 = 5 + 1 = Rs 6

So he bought 10 white sharpeners at Rs 6 each.

He also bought 8 brown sharpeners at Rs 5 each.