Quantitative Aptitude - Arithmetic Ability Questions

If a + b = 11 and a2+ b2= 61, then value of ab is

Find k, if the line 2x- ­3y = 11 is perpendicular to the line 3x + ky = -­4?

When a number is increased by 20, it becomes 116% of itself. What is the number?

The maximum value of 5+20x-4x2, when X is real number

If a merchant offers a discount of 20% on the list price, then he makes a loss of 10%. What % profit or % loss will she make if he sells at a discount of 5% of the list price?

What is the sum of first 40 terms of 1 + 3 + 4 + 5 + 7 + 7 + 10 + 9 + ....?

What is the value of 361+3.61+0.0361 ?

A, B and C can do a job working alone in 50, 75 and 20 days respectively. They all work together for 4 days, then C quits. How many days will A and B take to finish the rest of the job?