An office opens at $10 \, AM$ and closes at $5 \, PM$. The lunch interval is for $30$ minutes. The ratio of the lunch interval to the total office hours 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?

The present ages of $A$ and $B$ are in the ratio $5:6$ respectively. After seven years,this ratio becomes $6:7$. Then the present age of $A$ in years is:

If $B: A = 2: 3$ and $A: C = 5: 7$,then what is $(A + B) : (B + C)$?

If $A: B = \frac{1}{2}: \frac{3}{8}$,$B: C = \frac{1}{3}: \frac{5}{9}$ and $C: D = \frac{5}{6}: \frac{3}{4}$,then the ratio $A: B: C: D$ is

If $0.75 : x :: 5 : 8,$ then $x$ is equal to