A triangle is circumscribed on the circle of centre O in such a way that sides AB = 12 cm, BQ = 7 cm and CQ = 5 cm. Calculate the lengtth (in cm) of side AC.
In a certain code language, '÷' represents '+', '-' represents 'x', '+' represents '÷' and 'x' represents '-'. Find out the answer to the following question.
In a row of boys, Amit is ranked 12th from top and Ratan is 15th from bottom. They interchange their position. Ratan now becomes 37th from bottom. How many total boys are there in the row?