Quantitative Aptitude - Arithmetic Ability Questions

The average age of eight teachers in a school is 40 years. A teacher among them died at the age of 55 years whereas another teacher whose age was 39 years joins them. The average age of the teachers in the school now is (in years)

The sum of ages of 4 children born at intervals of 4 years each is 60. What is the age of the youngest child?

The average of first 20 multiples of 12 is

In each of the following questions, a question is followed by information given in them Statements I, II and III. You have to study the question along with the statements and decide the information given in which or the statements/ is necessary to answer the question. 

What is the cost of flooring the rectangular hall?

I. Length and the breadth of the hall are in the ratio of 3:2

II. Length of the hall is 48 m and cost of flooring is ₹ 850 Per sq.m.

III. Perimeter of the hall is 160 m and cost of flooring is ₹ 850 per sq m

The average revenues of 11 consecutive years of a company is Rs 77 lakhs. If the average of first 6 years is Rs 72 lakhs and that of last 6 years is Rs 84 lakhs, What is the revenue for the Sixth year.

Wheat costing Rs 30/kg, Rs 35/kg and a third variety of wheat are mixed in the ratio of 3 : 4 : 2. If the mixture is costs Rs 34/kg, then what will be the cost (in Rs/kg) of the third variety of wheat?

What is 15% of 34 ?

If 31% of an electricity bill is deducted, Rs 1794 is still to be paid. How much was the original bill amount?