Question

cost of a pencil is 10 times more than the cost of an eraser if the cost of 5 pencils and 4 eraser is rupees 40 find the cost of each​

Answer 1

let the cost of pencils be x and the cost of eraser be y

x = 10y ---------- 1

5x + 4y = 40 ----------- 2

substituting 1 in 2

5(10y) + 4y = 40

50y + 4y = 40

54y = 40

y = 40/54

y = 20/27

------------

x = 10 y

x = 200/27

hope it helps you

Answer 2

Concept

If there are 2 numbers a and b and it is given that a is x times b, then a = xb.

Given

cost of a pencil is 10 times more than that of an eraser.

and cost of 5 pencils and 4 eraser is rupees 40

Find

we need to find the cost of one pencil and one eraser.

Solution

Let cost of eraser be x

then cost of pencil = 10x

Cost of 5 pencils = 50x

cost of 4 erasers = 4x

We know

50x + 4x = 40

54x = 40

x = 40/54

x = 20/27

x = 0.74

and thus, 10x = 7.4

Therefore, the cost of a pencil is 7.4 rupees and eraser is 0.74 rupees.

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