Question

The cost of petrol is 75 per litre. What will be the new cost, if the cost of petrol is increased by 5%​

Answer 1

Answer:

75×5/100

= 3.75

75+3.75

78.75

Answer 2

Step-by-step explanation:

$\huge \underline \mathfrak \green{answer}$

• Let the original price of one-litre petrol be Rs.75

In Rs.1320 we obtain

$\frac{1320}{x}$

• litres of petrol at this rate

• the price is increased by Rs.5, then the new price of petrol is Rs. (x+5) per litre.

Then,

in Rs. 1320 we obtain

$\frac{1320}{x}$

at the new price

• condition, one gets 2 liters less petrol on spending Rs.1320

➢formula

petrol obtained that old price - petrol obtained that old price

$.'.\frac{1320}{x} - \frac{1320}{x + 5} = 2$

.'. 1320 (x+5)- 1320 x=2x(x+5)

∴ 1320x+6600−1320x=2x² +10x

∴ 2x² +10x−6600=0

∴ x²+5x−3300=0

∴ x² +60x−55x−3300=0

∴ (x+60)(x−55)=0

∴ x=−60 or x=55

But x= -60 is a not possible

➢because petrol is not negetive

so x=50

➢The old price of petrol is Rs.55/litre and the increased price is Rs.60/litre

The old price of petrol is Rs.55/litre and the increased price is Rs.60/litre