Question

The total cost of 6 books and 7 pens is 79 rupees and the total cost of 7 books and 5 pens is 77 rupees. Find the cost of 1book and 2pens

Answer 1

6 books and 7 pens is 79 rupeez
total cost of 7 books and 5 pens is 77 rupees.

let book x and pen you

therefore 6x+7y=79 -----'----'''----1
7x+5y=77------------------2

equating eqn

multiply eqn 1 by by 5
"""""""""""""""""2""""""""7

then; 30x+35y=395
49x+35y=539
substituting eqn _ _ =_
_x=_144
cut _ both sides
therefore x=144

put x in eqn 2nd

####
7x+5y=77
7 (144)+5y=77
1008 +5y =77
5y=77_1008
5y=_931
y=_186•2



cost of book is 144
cost of 2 pen is (186•2×2)=372. 4