Quantitative Aptitude - Arithmetic Ability Questions

ΔDEF is right angled at E. If cosecD = 25/24, then what is the value of cosF ?

Which of the following statements is/are TRUE?

$$\begin{gathered} 1. 64 + 0.64 + 0.0064 = 8.88 \\ 2. 81 + 0.81 + 0.0081 = 9.09 \end{gathered}$$

In a class, 30% of the students offered English, 20% offered Hindi and 10% offered both. If a student is selected at random, what is the probability that he. has offered English or Hindi ?

Calculate the area (in sq.cm) of a circle whose diameter is 14 cm.

When 0.232323.... is converted into a fraction , then the result is 

Calculate the area (in cm2) of a circle whose diameter is 7 cm.

Solve the following

78 ÷[-4 + -3 of 27 ÷ -18 ÷ -2]

If x + y + z = 6 and xy + zx + zy = 10, then find the value of x3 + y3 + z3 - 3xyz