In an election between two candidates,one got $55 \%$ of the total valid votes,and $20 \%$ of the total votes were invalid. If the total number of votes was $7500$,what was the number of valid votes that the other candidate received?

One side of a square is increased by $30 \%$. To maintain the same area,the other side will have to be decreased by:

The average marks obtained in a class of $50$ students is $70 \%$. The average of the first $25$ students is $60 \%$ and that of the next $24$ students is $80 \%$. What is the percentage of marks obtained by the last student?

$A$ batsman scored $110$ runs which included $3$ boundaries and $8$ sixes. What per cent of his total score did he make by running between the wickets?

If $35 \%$ of a number is $12$ less than $50 \%$ of that number,then the number is:

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 $40^{\circ}C$?