There is a ratio of $5:4$ between two numbers. If $40\%$ of the first number is $12$,then $50\%$ of the second number is:

$A$ man spends $Rs. 2310$ on an average during the first $8$ months from his income. During the next $4$ months,he spends $Rs. 1800$ on an average from his income,but he had taken a loan of $Rs. 1680$ apart from his income to meet his expenses. If he spent all that he had,what is the ratio of his average income to his average expenditure?

What will be $32 \%$ of $(\frac{3}{8})^{th}$ of $1000$?

The mean proportional between $64$ and $81$ is

Ajay,Aman,Suman,and Geeta rented a house and agreed to share the rent as follows:
Ajay:Aman $= 8: 15$,Aman:Suman $= 5: 8$,and Suman:Geeta $= 4: 5$. The part of the rent paid by Suman will be

The price of a diamond is directly proportional to the square of its weight. $A$ man accidentally broke the diamond into three pieces in the ratio of $3:5:7$ and thus lost ₹ $42600$. What was the original price (in ₹) of the diamond?