The present ages of Reena and Usha are $24$ and $36$ years,respectively. What was the ratio between the ages of Usha and Reena $8$ years ago?

The ratio of $4^{3.5} : 2^{5}$ is the same as:

In a mixture of petrol and kerosene,the quantity of petrol is $99 \text{ litres}$. If this same quantity of petrol were present in another mixture of petrol and kerosene where the total volume is $198 \text{ litres}$ less than the actual mixture,the concentration of petrol in the actual mixture would be $13.33 \%$ less than that of the new mixture. What is the concentration (in $\%$) of petrol in the actual mixture?

Mr. Pandit owned $950$ gold coins,all of which he distributed among his three daughters Lalita,Amita,and Neela. Lalita gave $25$ gold coins to her husband,Amita donated $15$ gold coins,and Neela made jewellery out of $30$ gold coins. The new respective ratio of the coins left with them was $20:73:83$. How many gold coins did Amita receive from Mr. Pandit?

If $33 \%$ of $A$ is equal to $55 \%$ of $B$,then find the ratio of $A$ and $B$.

Gold is $19$ times as heavy as water and copper is $9$ times as heavy as water. In what ratio should these be mixed to get an alloy $15$ times as heavy as water?