Solution:

Let price of tea be Rs `100` per kg
`:.` new price of tea = Rs `( 100 + 20 )` = Rs `120` per kg
Now not to increase the expenditure, its consumption must be reduced by Rs `20`
New Price Rs  Reduced Consumption Rs  120  20  100  ?  Reduced Consumption = `(100 × 20) / 120 = 16.6667` Rs
`:.` Consumption must be reduced by Rs `16.6667` , if original price of tea be Rs `100`
`:.` Consumption must be reduced by `16.6667` % for not to increase the expenditure.


