Quantitative Aptitude - Arithmetic Ability Questions

Triangle DEF is right angled at E. If cot D = 5/12, then what is the value of sin F?

Present age of Amit is twice of Baman’s present age. After 5 years Baman’s age will be 4 times of the Chetan’s present age. If Chetan celebrated his sixth birthday 7 years ago, then what will be the present age (in years) of Amit?

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

If x + [1/(x + 7)] = 0, then what is the value of x – [1/(x + 7)]?

The numbers x, y, z are respectively proportional to 2, 3, 5 and the sum of x, y and z is 80. If the number z is given by the equation z = ax­-8, then a is

Rs. x invested at 8% simple interest per annum for 5 years yields the same interest as that on Rs. y invested at 7.5% simple interest per annum for 6years. Find x : y.

Find the sum of interior angles of a dodecagon?

D and E are points on side AB and AC of ΔABC. DE is parallel to BC. If AD:DB = 2:5 and area of ΔADE is 8 cm sq, what is the area (in sq cm) of quadrilateral BDEC?