The price of rice is reduced by $2 \%$. How many kilograms of rice can now be bought for the money which was sufficient to buy $49 \text{ kg}$ of rice earlier?

$A$ speaks truth in $80 \%$ of the cases and $B$ in $90 \%$ of the cases. Find the percentage when they contradict each other in describing the same facts. (in $\%$)

$A$ person's salary has increased from $Rs. 7200$ to $Rs. 8100$. What is the percentage increase in his salary (in $\%$)?

In a recent survey,$40 \%$ of houses contained two or more people. Of those houses containing only one person,$25 \%$ had only a male. What is the percentage of all houses that contain exactly one female and no males (in $\%$)?

Two numbers are respectively $20 \%$ and $30 \%$ less than a third number. What is the second number as a percentage of the first?

If inflation increases at a rate of $8 \%$ p.a.,what will a $₹ 20$ article cost at the end of two years?