The average age of a class of 40 students and a teacher reduces by 0.5 years, if we exclude the teacher. If the initial average age is 18 years, then what is the age of the teacher?

Divide 32 into two parts such that the sum of the square of the parts is 674 what is the value of the parts? 

The greatest number, which when divides 989 and 1327 leave remainder 5 and 7 respectively: 

Study the given graph carefully to answer the questions that follow:

If carpenter X, Y and Z were to make a table together how many days would they take?

The income of A is 25% more than that of B and the income of C is 65% less than the sum of the incomes of A and B. Income of C is what percent less than the income of A?

The difference between a discount of 30% on ₹ 2,000 and two successive discounts of 25% and 5% on the same amount is 

Ratio of age of father, mother and son is 9:8:3. Five years hence sum of their age will be 95 years. Find the age of son 5 years ago.

Direction: what should come in place at question mark(?).

$$ {1\over 8}×(223+?)=71$$