If the price of sugar is increased by $7%$, then by how much per cent should a housewife reduce the consumption of sugar, to have no excess expenditure
Let family consume $100$ units of sugar. Price of $1$ unit is $\$100$. Total expenditure is $\$10,000$.
Now new expenditure will be $\$10,700$.
So we have $700$ as extra expenditure. So units which are extra are $700/107$.
Hence we have to reduce consumption by $700/107=6.542\%$.
But textbook writes as $7/107$ percent. Can someone explain to me this? Am I wrong or textbook?