Question

3 bags and 4 pens together costs rs 257 whereas 4 bags and 3 pens together costs rs 324 and find the total cost of 1 bag and 10 pens

Answer 1

♠Answer♠

Let Cost of a Pen be 'x'
& That of a bag be 'y'

now , 3y+4x=257

and , 4y+3x=324

On Solving these Equations ,

Once Add both and Then Subtract both , With Each Other ..

you Shall Get

x + y = 83

x- y = 67

So , x = 75

y = 8

Which were the costs respectively !

Then cost of 1 bag and 10 pen will be Rs.155

#SupermanINFINITY

Answer 2

let,
cost of bag be'x'
cost of pen be'y'
then,
3x+4y=257
4x+3y=324
now
4x+3y=324
-(3x+4y=257)
---------------------
x - y = 67
----------------------
x-y=67
x=67+y

now substitute in any one of them

4x+3y=324
4(67+y)+3y=324
268+4y+3y=324
268+7y=324
7y=324-268
7y=56
y=56/7
y=8

now substitute y value in any one of them

4x+3y=324
4x+3(8)=324
4x+24=324
4×=324-24
4×=300
x=300/4
x=75


::cost of pen(y)=8
::cost of bag(x)=75

total cost of 1 bag and 10 pen ;
1(75)+10(8)=75+80
=155

total cost of 1 bag and 10 pens =rs.155