Question

solve this question

Answer 1

Let Cost of 1 kg tea=₹x
Cost of 1 kg sugar=₹y
Total cost=₹700
Cost of return ticket=₹50
Total tea=1.5x
Total sugar=5y
Cost of tea and sugar=total cost-cost of return ticket
=700-50
=₹650
Making the linear equation for this.
1.5x+5y=₹650
=>5y=650-1.5x
=>y=130-0.3x
Also,
1.5x+5y-650=0
Let it be equation 1

Now,
Cost of 2 kg tea=2x
Cost of 7 kg sugar=7y
Cost of this=₹880
Linear equation in 2 variable for this is
2x+7y=880
=>2x+7y-880=0
Let it be equation 2

Putting equation 1 in 2
1.5x+5y-650=2x+7y-880
=>-650-(-880)=2x-1.5x+7y-5y
=>-650+880=0.5x+2y
=>230=0.5x+2y
OR
0.5x+2y=230
Let it be equation 3

Putting y as 130-0.3x in equation 3
0.5x+2(130-0.3x)=230
=>0.5x+260-0.6x=230
=>0.5x-0.6x=230-260
=>-0.1x=-30
OR
0.1x=30
=>1/10x=30
=>x=30x10
=>x=300

For y
y=130-3/10x
=130-3/10x300
=130-3x30
=130-90
=40

Therefore we conclude that the cost of tea is ₹300/kg and cost of sugar is ₹40/kg