Quantitative Aptitude - Arithmetic Ability Questions

Reflection of the point (­1,4) in the x­axis is

The average cost of 5 items in a shopping list is Rs 650. If one more item whose cost is Rs 1400 is added to the list what will be the new average (in Rs)?

The mean of 12 observations is 15. One more observation is included and the new mean becomes 16. The 13th observation is

The simple interest on a sum for 5 years is Rs 16800. The rate of interest for the first 3 years is 8% per annum and for the next 2 years is 12% per annum. What is the value (in Rs) of sum?

A sum of money (P) doubles in 10 years. How much would it be in 20 years at the same rate of simple interest?

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?

PQ is a diameter of a circle with centre O. RS is a chord parallel to PQ subtends an angle of 40° at the centre of the circle. If PR and QS are produced to meet at T, then what will be the measure (in degrees) of ∠PTQ?

If x2 + ax + b, when divided by x + 3, leaves a remainder of -1 and x2 + bx + a, when divided by x - 3, leaves a remainder of 39, then a+ b = ?