Quantitative Aptitude - Arithmetic Ability Questions

The average age of eight teachers in a school is 40 years. A teacher among them died at the age of 55 years whereas another teacher whose age was 39 years joins them. The average age of the teachers in the school now is (in years)

Both X and Y together can complete a work in 12 days and Y alone can complete the same work in 30 days. In how many days will X alone complete the work?

Wheat costing Rs 30/kg, Rs 35/kg and a third variety of wheat are mixed in the ratio of 3 : 4 : 2. If the mixture is costs Rs 34/kg, then what will be the cost (in Rs/kg) of the third variety of wheat?

The sum of a non-zero number and its reciprocal is 2. What is the number?

In what ratio is the segment joining the points (2,5) and (­6,­10) divided by the y­axis?

In ΔPQR, S and T are points on side PQ and PR respectively. ST is parallel to QR. If S divides PQ in the ratio 1:5 and length of QR is 15 cm, find ST?

A kite is flying in the sky. The length of string between a point on the ground and kite is 420 m. The angle of elevation of string with the ground is 30 deg. Assuming that there is no slack in the string, then what is the height (in metres) of the kite?

What is the value of (cot30°+ 2/√3) ?