The price o petrol rose by 10%. By how consumption should be reduced so that expenditure does not increase.

Explanation

Let the consumption of petrol =` 1 `unit and its cost = `Rs.100`
New cost of `1` unit of petrol = `Rs.110`
Rs.110 will yield 1 unit of petrol
`Rs.100` will yield `(1/110 xx 100) `
`10/11` unit of petrol
Now,Reduction of consumption
`1 – (10/11) `
`1/11`
Reduction of consumption
`1 – (10/11)`
`1/11 `
Percentage of reduction
`(1/11 xx 100) % `
`9 1/11 %`