The average of five numbers is  27.  If one  number is excluded. The average becomes 25. The excluded number is

The average marks of the students of a class is 68. The average marks of girls in the class is 80 and that of boys is 60. What percentage of students are boys in the class?

If $$ {y\over x-z}={y+x\over z}={x\over y}$$ the find x:y:z is?

Two buses travel to a place at 45 km/hr and 60 km/hr respectively. If the second bus takes 5½ hours less than the first for the journey, the length of the journey is:

Find the area of triangle whose medians are 8 cm, 15 cm and 17 cm respectively?

The length, breadth and height of a room are in the ratio 7:3:1. If the breadth and height are doubled while the length is halved, then by what percent the total area of the 4 walls of the room will be increased?

Find the exact value of the following question:

$$ 3{1\over2} × 3 {1\over 7}+ 5{3\over4}÷{46\over3}=?$$

A number is divided by 6 and 5 is added to this quotient Again sum is divided by 9 and the quotient obtained is 1. Find the number.