Dr. K. Kautilya Solutions for Chapter: Mathematical Aptitude, Exercise 10: Exercise

Average age of $30$ boys in a class is $10$ years. If, however, the age of their teacher is also included, then the average increases by one year. What is the age of the teacher?

The average of $3$ numbers is $7$ and average of the first two numbers is $5.$ What is the third number?

A motorist completes the journey between A and B at a constant speed of $20 \mathrm{kmph}$ and covers the returns journey from B to A at a constant speed of $30 \mathrm{kmph}.$ What was the average speed?

The average age of three persons is $45$ years, their ages are in the ratio of $2:3:4.$ The difference between the ages of the youngest and the eldest is-

The average of the runs scored by a cricket eleven is $50.$ If the runs scored by the captain is excluded, the average score rises by $5.$ How many runs did the captain score?

The average of three numbers is $77.$ The first number is double of the second, the second is double of the third. The numbers are -

The average of two numbers is $180.$ If one of them is half the other, the numbers are -

The average of three numbers of which greatest is $16$ is $12.$ If the smallest is half of the greatest, the remaining number is: