Question

If the cost of 37 pens and 53 pencils together is ₹320, while 53 pens and 37 pencils together cost ₹400. The cost of
two pens is? ​

Answer 1

${\huge{\purple{\underline{\underline{\mathbb{\pink{ANSWER}}}}}}}$

Given :

$\bold\red{IN\:Ist \:CASE}$

Number of pens = 37

Number of pencils = 53

Together cost = Rs 320

$\bold\green{IN\:IInd\:CASE}$

Number of pens = 53

Number of pencils = 37

Together cost = Rs 400

To find : The cost of a pen and that of a pencil.

Let the cost of the pen be Rs " x "and

That of pencil be Rs " y ".

$\bold\purple{According\:to\:question}$

37x + 53y = 320  --------- ( i )

and, 53x + 37y = 400  ------ ( ii )

$\bold\green{Add\:eqs\:(i)\:and\:(ii)}$

$\bold\orange{THEN,\:WE\:GET:}$

90x + 90y = 720 ⇒ x + y = 8    ----- ( iii )

$\bold\pink{Substract\:eqs\:(i)\:and\:(ii)}$

$\bold\purple{WE\:GET:}$

16x - 16y =  80 ⇒ x - y = 5   ----------- ( iv )

$\bold\orange{Add\:eqs\:(iii)\:and\:(iv)}$

$\bold\pink{THEN,\:WE\:GET:}$

2x = 13 ⇒ x = 6.5

x= 6.5

$\bold\red{Subtract}$ x = 6.5 in equation ( iii )

$\bold\blue{WE\:GET:}$

y = ( 8 - 6.5 )

y= 1.5

Answer 2

Answer:

Refers to this Attachment

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