Question

The cost of 4 pens and 8 pencils is rs 84. if one pen costs rs12 more than the cost of one pencil, find the cost of one pen and pencil separately

Answer 1

x=pens
y=pencil
therefore

Answer 2

4x+8y=84
divide whole equation by 4
we get ,
x+2y=21 ••••••••(1)

and,
x-y=12 •••••••••(2)

solve equation 1&2
we get,
cost of pen(x) = 15 Rs
cost of pencil(y)= 3 Rs