Quantitative Aptitude - Arithmetic Ability Questions

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

PQR is a right angled triangle in which PQ = QR. If the hypotenuse of the triangle is 20 cm, then what is the area (in cm2) of the triangle PQR?

If tan θ + cot θ = x, then what is the value of tan4θ + cot4θ?

If 2secA - (1 + sinA)/cosA = x, then the value of x is

A train is moving at the speed of 72km/hr. How many seconds will it take to cover a distance of 1400 m ?

If 27N4 is divisible by 11, then what is the value of N?

Point Q(-1,b) is the midpoint of segment EF. Co-ordinates of point E are (-4,a) and point F are (2,0). What is the value of a and b?

Seven years ago, the average age of A, B and C was 51 years. If A is 3 years older than B and B is 3 years older then C then the present ages of A, B and C are ( in year)