Math, asked by Thunder8515, 1 month ago

The cost of 5 pens and 8 pencils is 120 while the cost of 8 pens and 5 pencils is Rs 153.Find the cost of 1 pen and that of 1 pencil.

Answers

Answered by oppoa302610
6

Answer:

Cost of pen =Rs.16

and cost of pencil =Rs.5

explanation

Let the cost of one pen is Rs.x and cost of one pencil is Rs.y, then

As per statement

5x+8y=120...(1)

8x+5y=153...(2)

Adding both the equations, we get

13x+13y=273

x+y=21....(3)

On subtracting (1) from (2),

3x−3y=33

x−y=11...(iv)

Again

Adding (3) and (iv).

2x=32 or x=16

On subtracting

2y=10 or y=5

Answered by TheBrainliestUser
14

Given that:

  • The cost of 5 pens and 8 pencils is 120.
  • The cost of 8 pens and 5 pencils is Rs 153.

To Find:

  • The cost of 1 pen and that of 1 pencil.

Let us assume:

  • The cost of 1 pen = x
  • The cost of 1 pencil = y

According to the question.

ㅤ↠ㅤ5x + 8y = 120 (i)

ㅤ↠ㅤ8x + 5y = 153 (ii)

Adding eqⁿ (i) & eqⁿ (ii).

ㅤ↠ㅤ13x + 13y = 273

ㅤ↠ㅤx + y = 21

Subtracting eqⁿ (ii) from eqⁿ (i).

ㅤ↠ㅤ-3x + 3y = - 33

ㅤ↠ㅤx - y = 11

Now,

ㅤ↠ㅤx - y = 11 (iii)

ㅤ↠ㅤx + y = 21 (iv)

Adding eqⁿ (iii) & eqⁿ (iv).

ㅤ↠ㅤ2x = (11 + 21)

ㅤ↠ㅤx = 32/2 = 16

Putting the value of x in eqⁿ (iv).

ㅤ↠ㅤ16 + y = 21

ㅤ↠ㅤy = 21 - 16

ㅤ↠ㅤy = 5

Hence,

  • The cost of 1 pen = Rs. 16
  • The cost of 1 pencil = Rs. 5
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