Question
An elephant can do a work as fast as two horses ‘A’
and ‘B’ can do it by working together. If horse ‘A’ alone can complete the work in 20 hours and horse ‘B’ in 30 hours, then find the time taken by elephant to complete the work.Solution
Let the total work = 60 units Efficiency of horse who can complete the work in 20 hours = 60/20 = 3 units/hour Efficiency of horse who can complete the work in 30 hours = 60/30 = 2 units/hour Therefore, time taken by both horses to complete the work together = 60/(3 + 2) = 12 hours Therefore, time taken by the elephant to complete the work = 12 hours
A square whose diagonal is 12√ 2cm is made base of the pyramid. if height of the pyramid is 15cm, then what is the total surface area of the pyramid.(...
Find the area of the largest circle that can be drawn in a square of side 28 cm.
A storeroom has only steel and copper rods in the ratio 3:4, respectively and the weight of each steel and each copper rod is in the ratio 5:8, respecti...
Ratio of length to width of a rectangular field is 7:4. If the perimeter of the field is 220 metres, then find the area (in m2) of the field.
A right circular cylinder having diameter 21 cm & height 38 cm is full of ice cream. The ice cream is to be filled in cones of height 12 cm and diameter...
- A storehouse measures 36 metres long, 15 metres wide and 12 metres high. If each storage box requires 90 m³ of space, how many storage boxes can fit insid...
Two equal vessels A and B contain 70% of milk and 60% of milk respectively and the remaining sugar. In which 30 kg of mixture is taken out from vessel A...
Perimeter of square is 48 cm and length of a rectangle is equal to side of square and breadth of rectangle is 4 cm less than length of the rectangle. F...
- A rectangle has a length of 22 cm and a width of 6 cm. A square has the same perimeter as this rectangle. What would be the circumference of a semicircle w...
The volume of a cube is 64 cm³. If the cost of painting the cube is Rs. 15 per cm², then find the cost of painting five faces of the cube.
