In an examination,there are $1000$ boys and $800$ girls. $60 \%$ of boys and $40 \%$ of girls passed. The percentage of candidates that failed is: (in $\%$)

On decreasing the price of a colour $TV$ by $30 \%$,its sale is increased by $20 \%$. The effect on the revenue is:

If $A$ is $150 \%$ of $B$,then $B$ is what percent of $A+B$?

Mr $X$ invested a certain amount in Debt and Equity Funds in the ratio of $4:5$. At the end of one year,he earned a total dividend of $30\%$ on his investment. After one year,he reinvested the amount including the dividend in the ratio of $6:7$ in Debt and Equity Funds. If the amount reinvested in Equity Funds was $Rs$ $94,500$,what was the original amount invested in Equity Funds (in $,000$)?

$A$ student has to secure $15\%$ marks to pass the examination. If he gets $80$ marks and fails by $70$ marks,find the maximum marks set for the examination.

$45 \%$ of $1500 + 35 \%$ of $1700 = ? \%$ of $3175$