A family consists of a grandmother, father, mother, and their four sons with their respective wives. Further, each son has a daughter and two sons. How many females are there in all?

Some equations are solved on the basis of a certain system. Find out the correct answer for the unsolved equation on that basis.
If 8 + 8 = 72, 5+5 = 30 and 7+7=56, what is 6+6 =?

The sum of the ages of a father and his son is 56 years. After 4 years, the father's age will be 3 times his son's age. Their ages are respectively.

If “+” denotes ‘ – ‘ , ‘ – ‘ denotes ‘× ‘, ‘×’ denotes ‘÷’  and ‘÷’ denotes ‘+’, then what is the value of
15 – 5 +15 ÷ 45 × 15

If "÷" denotes "multiplied by", "+" denotes "subtracted from", "x" denotes "added to" and "–" denotes "divided by",then
12 – 6 + 28 × 3 ÷ 9 = ?

Which two signs should be interchanged to make the following equation correct?
5 + 3 x 8 - 12 ÷ 4 = 3 

Which two signs need to be interchanged to make the following equation correct?
45 – 9 ÷ 3 +5 ×6 =32

The ratio of the present age of the two brothers is 1: 2. And 5 years ago this ratio was 1: 3. So what will be the ratio of their age after 5 years.