Quantitative Aptitude - Arithmetic Ability Questions

Select the odd word/letters/number/number pair from the given alternatives.

9997 x 10003 = ?

If (secA - tanA)2 = x, then the value of x is

What is the mean of the first five Triangular Numbers?

A boy crosses a 300 metres wide road in 30 seconds. What is his speed (in km/hr)?

The traffic lights at four different road crossings change after every 15 sec, 18 sec, 27 sec and 30 sec respectively. If they all change simultaneously at 6:10:00 hours, then at what time will they again change simultaneously?

If r sinθ=3 and r cosθ=1, then the values of r and θ are: (0°⩽θ≤90°)

A, B and C can complete a work in 20, 24 and 30 days respectively. All three of them starts together but after 4 days A leaves the job and B left the job 6days before the work was completed. C completed the remaining work alone. In how many days was the total work completed?