If $378$ coins consist of $Rs. 1$,$50$ paise,and $25$ paise coins whose values are in the ratio of $13: 11: 7$,the number of $50$ paise coins will be:

The difference between the ages of Meena and Seema is $3 \ yr$ and the ratio between their ages is $7: 8$. What is the sum of their ages (in $yr$)?

On the entire Earth,the ratio between land and water is $1:2$,and in the Northern Hemisphere,this ratio is $2:3$. What will be the ratio of land to water in the Southern Hemisphere?

If $A: B = 8: 15$,$B: C = 5: 8$,and $C: D = 4: 5$,then $A: D$ is equal to:

The electricity bill of a certain establishment is partly fixed and partly varies as the number of units of electricity consumed. When in a certain month $540$ units are consumed,the bill is $Rs. 1800$. In another month $620$ units are consumed and the bill is $Rs. 2040$. In yet another month $500$ units are consumed. The bill (in $Rs.$) for that month would be:

If $A$ and $B$ are in the ratio $4:5$ and the difference of their squares is $81,$ what is the value of $A?$