Quantitative Aptitude - Arithmetic Ability Questions

The average age of a class of 39 students is 15 years. If the age of the teacher is included, then the average increases by 3 months. Find the age of the teacher.

What is the value of tan4A + tan2A?

If O is the orthocentre of a triangle ABC and ∠BOC = 100°, the measure of ∠BAC is

A fan is listed at Rs. 150 with a discount of 20% . What additional discount must be offered to the customer to bring the net price to Rs. 108 ?

After two successive discounts of 20% and 35%, an article is sold for Rs 50700. What is the marked price (in Rs) of the article?

Seven years ago, the average age of A, B and C was 51 years. If A is 3 years older than B and B is 3 years older then C then the present ages of A, B and C are ( in year)

In a class of 65 students there are 39 girls. The average weight of these girls is 60 Kg and average weight of the full class is 64 kgs. What is the average weight of the boys of the class?

The standard deviation of the set {10, 10, 10, 10, 10} is