Quantitative Aptitude - Arithmetic Ability Questions

A, B and C can do job in 9, 12 and 36 days respectively if they worked alone. A leaves after they have worked together for 3 days. In how many days can B and C do the rest of the job?

If a + a2 + a3 – 1 = 0, then what is the value ofa3 + (1/a)?

Of the 3 numbers whose average is 70, the first is 1/9 times the sum of other 2. The first number is

What is the value of sin 75°+ sin 15°?

What is the value of the expression a3 - 5 + 2816a, when a = 2?

If (X/4) = (Y/5) = (Z/9), then what is X : Y : Z?

By increasing the price of entry ticket to a fair in the ratio 17:19, the number of visitors to the fair has decreased in the ratio 11:10. In what ratio has the total collection increased or decreased?

The line passing through (-2,5) and (6,b) is perpendicular to the line 20x + 5y = 3. Find b?