Quantitative Aptitude - Arithmetic Ability Questions

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?

Vishal is 20 years younger to Arya. Twelve years hence Arya's age will be 1.25 times that of Vishal. Aryais now ......... years old.

The point equidistant from the vertices of a triangle is called its

If x+1x = 4, then what is the value of x6+1x6 ?

ABCD is a quadrilateral with AB = 9 cm, BC = 40 cm, CD = 28 cm, DA = 15 cm and angle ABC is a right –angel. 
What is the area of triangle ADC?

What is the value of Sin 30° - Cosec 45°?

A missile travels at 1278 km/h. How many metres does it travel in one second?

In the following question, select the odd letter/letters from the given alternatives.