What should be subtracted from $15, 28, 20,$ and $38$ so that the remaining numbers are in proportion?

$A, B, C$ and $D$ share a property worth $₹ 77500$. If $A:B = 3:2$,$B:C = 5:4$ and $C:D = 3:7$,find the share of $B$ (in $₹$).

One year ago,the ratio of Ramu's and Somu's ages was $6:7$ respectively. Four years hence,their ratio will become $7:8$. How old (in years) is Somu?

$A$ person's present age is two-fifth of the age of his mother. After $8$ years,he will be one-half of the age of his mother. How old is the mother at present (in $years$)?

An amount of $Rs. 2430$ is divided among $A$,$B$,and $C$ such that if their shares are reduced by $Rs. 5$,$Rs. 10$,and $Rs. 15$ respectively,the remainders are in the ratio of $3:4:5$. Then,$B$'s share was (in $Rs.$):

The number of students in three classes are in the ratio $2:3:4$. If $12$ students are increased in each class,this ratio changes to $8:11:14$. The total number of students in the three classes in the beginning was: