Quantitative Aptitude - Arithmetic Ability Questions

If a boat goes upstream at a speed of 21 km/h and comes back the same distance at 28 km/h. What is the average speed (in km/hr) for the total journey?

A can do a piece of work in 18 days. He worked at it for 12 days and B finished the remaining work in 8 days. B alone can do the whole work in

A man travelled a distance of 61 km. in 9 hours , partly by walking at speed of 4 km / hr and partly on bicycle at speed of 9 km / hr. The distance covered by walking is

During morning walk, a man covers a distance of 3 km, 4 km, 3.5 km, 5 km and 4.5 km from Monday to Friday, respectively. How much distance should he cover on two more days, so that his average per week becomes 4 km per day?

A solid cone of height 24 cm and radius of its base 8 cm is melted to form a solid cylinder of radius 6 cm and height 6 cm. In the whole process what
percent of material is wasted?

The side of an equilateral triangle is 14 cm. Find its area (in sq.cm).

A Number is increased by 20%. To get back to the orignal number, the increased number is to be reduced by

In the question, two equations I and II are given. You have to solve both the equations and give answer

$$\begin{gathered} x2-11x+28=0 \\ y2-18y+81=0 \end{gathered}$$