If the price of a shirt is increased by $25 \%$ and then decreased by $30 \%$,then what will be the net effect?

If $37 \frac{1}{2} \%$ of a number is $45,$ then $87 \frac{1}{2} \%$ of the number will be:

The monthly income of a person is $Rs. 5000$. If his income is increased by $30\%$,then what is his monthly income now?

Neha has a watch which gains $2 \%$ per hour when the temperature is in the range of $40^{\circ}C - 50^{\circ}C$ and it loses at the same rate when the temperature is in the range of $20^{\circ}C - 30^{\circ}C$. The watch runs on time in all other temperature ranges. On a sunny day,the temperature started rising from $8$ $a.m.$ at a uniform rate of $2^{\circ}C$ per hour and during the afternoon it started falling at the same rate. Find what time will it be by the watch at $7$ $p.m.$ if at $8$ $a.m.$ the temperature was $32^{\circ}C$ and at $4$ $p.m.$ it was $40^{\circ}C$?

An index of $12$ shares contains,among others,the shares of Vision Power,Vision Infra,and Vision Communication with weightage of $7\%$,$13\%$,and $15\%$ respectively. What is the increase in the prices of other shares,if these three rise by $9\%$,$10\%$,and $4\%$ respectively,while the index rises by $6\%$?

The difference between a discount of $35 \%$ and two successive discounts of $20 \%$ and $20 \%$ on a certain bill was ₹ $22$. Find the amount of the bill.