Quantitative Aptitude - Arithmetic Ability Questions

In a mixture of milk and water, there is 19% milk. If the quantity of milk in the mixture is 437 mililitres, then what is the total quantity (in millilitres) of mixture?

In ∆ ABC, the height CD intersects AB at D. The midpoints of AB and BC are P and Q respectively. If AD = 8 cm and CD = 6 cm, then the length of PQ is?

Two donkeys are standing 400 meters apart. First donkey can run at a speed of 3 m/sec and the second can run at 2 m/sec. If two donkeys run towards each other after how much time (in sec) will they bump into each other?

Average of the marks of 132 students of a college is 40. If the average of the marks of the passed students is 42 and the average of the marks of the failed students is 20, then what will be the respective ratio of the total marks of passed students and the total marks of failed students?

Two circles are having radii 9 cm and 12 cm. The distance between their centres is 15 cm. What is the length (in cm) of their common chord?

What is the value of cot 11π/6?

A tetrahedron has 4 vertices. How many edges does it have?

If a2+1a2 = 38, then find the value of a-1a?