Question

The cost of 3 pens, 4 erasers and 5 sharpners is rs 40. the cost of 5 pens ,7 eraser and 9 sharpeners is rupees 70 find the total cost of one of Each.​

Answer 1

Answer:

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Suppose one eraser, one sharpener and one pencil cost e,s and p rupees respectively.

Given:

5e+7s+9p=100 .... (1) and 2e+6s+10p=80 .... (2)

So, from (2) 

e+3s+5p=40 ⟹ e=40−3s−5p

Substituting in (1) we get,

5(40−3s−5p)+7s+5p=40 by solving we get s=10−2p .... (3)

Substitute in (2) we get,

e−p=10 .... (4)

Adding (3) and (4) we get,

e+s+p=20.

Answer 2

Answer:

Let the cost of each pen, eraser and sharper be p, e and s respectively.3p + 4e + 5s = 40→(1)5p + 7e + 9s = 70 →(2)Multiplying the equation (1) by 2 and subtracting the equation (2) from it, we get, p + e + s = 10Hence the total cost of one of each is `10

Step-by-step explanation: