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?

If $m : n = 3 : 2,$ then $(4m + 5n) : (4m - 5n)$ is equal to:

The ratio of the ages of the father and mother was $11: 10$ when their son was born. The ratio of the ages of the father and mother will be $19: 18$ when the son is twice his present age. What is the ratio of the present ages of the father and mother?

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?

Two numbers are in the ratio $2:3$. If $2$ is subtracted from the first and $2$ is added to the second,the ratio becomes $1:2$. The sum of the numbers is:

On Republic Day,sweets were to be equally distributed among $450$ children. But on that particular day,$150$ children remained absent. Thus,each child got $3$ sweets extra. How many sweets did each child get?