Question

The price of 8 litre of mustard oil and 5 litre of ground nut oli together is rs1150. If the price of mustard oil increases by 10% and that of ground nut oil by 20% the price of the two is 1310 rs..find out the price of per litre of both oil

Answer 1

Answer:

Cost of mustard oil = Rs 87.50

Cost of ground nut oil = Rs 90.00

Step-by-step explanation:

Let the mustard oil cost per litre be m and that of ground nut oil be g

∴ ×

∴ 8m+5g=1150 ........eqn 1

Now, as the price of mustard oil increases by 10%, new price will be (m+10m/100) = 1.1m

Similarly, the price of ground nut oil has increased by 20%, hence the new price will be (g+20g/100) = 1.2g

∴ 8(1.1m)+5(1.2g)=1310

8.8m + 6g=1310 ........... eqn 2

Now, these two equations are a pair of linear equations in two variables (m and g)

Using the elimination method, we shall multiply eqn 1 by 6 & eqn 2 by 5 to eliminate g

∴ 48m+30g=6900 ........... eqn 3

and 44m+30g=6550 ........... eqn 4

Subtracting eqns 3 & 4, we get

4m=350

∴ m=87.5

Now putting this value in eqn 1, we get

700+5g=1150

5g=1150-700

5g=450

∴ g=90

Hence, the cost per litre of mustard oil is Rs 87.50

and the cost per litre of ground nut oil= Rs 90.00