Quantitative Aptitude - Arithmetic Ability Questions

What is the simplified value of tan (θ/2) + cot (θ/2)?

A, B and C can finish a job working alone in 20, 30 and 60 days respectively. They all work together for 1 day, then A and B quit. How many days C working alone will take to finish the remaining part of the job?

The average revenues of 13 consecutive years of a company is Rs 78 lakhs. If the average of first 7 years is Rs 73 lakhs and that of last 7 years is Rs 85 lakhs, what is the revenue for the 7th year?

The mean of marks secured by 35 students in division A of class X is 65, 45 students of division B is 61 and that of 70 students of division C is 59. What is the mean of marks of the students of three divisions of Class X?

What is the mean of the first five Triangular Numbers?

The average marks obtained by a group of 10 students were 20. One student left the group as a result of which the average of the remaining students rose to 21. But another student joined, as a result of which the average marks of the group dropped a bit and became 20.6. What were the average marks obtained by the student who left and the one who joined?

If 3x - 8(2 - x) = -19, then the value of x is

A 1.6 m tall observer is 45 meters away from a tower. The angle of elevation from his eye to the top of the tower is 30°, then the height of the tower in meters is