Quantitative Aptitude - Arithmetic Ability Questions

PQRS is a square whose side is 20 cm. By joining opposite vertices of PQRS are get four triangles. What is the sum of the perimeters of the four triangles?

If Tan θ = 9/40, then Sec θ = ?

If I walk at 7/6 of my usual speed, then I reach my office 15 minutes early. What is the usual time taken (in minutes) by me to reach the office?

If (1/cos θ) – (1/cot θ) = 1/P, then what is the value of cos θ?

In a class of 60 students there are 20 girls who scored an average of 40 marks in the test, what is the average marks of the boys if the class average is 60 marks?

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

If (23)2= 4x then 3x is equal to

If 3P/5 = 7Q/2 = 7R/5, then what is the ratio of p, Q and R respectively?