Question

price of 6 books is rupees 3000 / 7 and price of 10 pens is rupees 1200/11 then find the price of 3 books and 4pens​

Answer 1

Answer:

Brainly.in

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Secondary School Math 5 points

The total cost of 6 books and 7 pens is 79 rupees and the total cost of 7 books and 6 pens is 77 rupees. find the cost of 1 book and 2 pens.

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Answers

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tarun56

tarun56 Ambitious

Let the cost of the book be x

And the cost of pen be y

Then the cost of 6 books n 7 pens is

6x+7y = 79

And 7x+6y = 77

Now let us add both equations

13x + 13y = 156

X+y = 12

Let us subtract both equations

-x + y = 2

Now let us add the equations so obtained then

X-x + y +y = 12 + 2

2y = 14

y = 7

Substitute in one equation then

X + 7 = 12

X = 5

So the cost of one book is 5

And one pen is 7

So the cost of 1 book and 2 pens is

X + 2y = 5 + 2(7) = 5 + 14 = 19

Answer 2

Answer:

this is the correct answer