Question
The average number of books on history, polity and
geography in a library is 190, and the average number of books on history and geography is 160. If the number books on geography is 20% less than the number of books on polity, then what is the number of books on history in the library?Solution
Let the number of books on History, Polity and Geography be x, y and z respectively. Given, (x + y + z)/3 = 190 Or, x + y + z = 570 ….. (1) And, (x + z)/2 = 160 Or, x + z = 320 ….. (2) From equation 1 and 2 Number of books on polity = y = 250 Number of books on geography = 0.8 × 250 = 200 Therefore, number of books on history = 570 – (250 + 200) = 120
If the cube with a 24√3 cm diagonal is melted then how tall is the height of the cuboid, if the length of the cuboid is equal to the arm of the cube, ...
The perimeter of a rectangular field is 22 metres and its area is 20 m^2 . What is the length of the diagonal of this field?
The volume of a solid cube is 729 m3. If whole cube is to be painted at a rate of Rs. 8 per m2, then what will be the cost of pain...
If the area of a square field is 576 m 2 , then find the diagonal of the square field.
<p><p>The length of sides of a square is twice the radius of a circle and perimeter of a rectangle is half the perimeter of the squa...
Calculate the area of the square whose perimeter is equal to the perimeter of a rectangle which has length 22 cm & breadth 14 cm .
Perimeter of a square is equal to the perimeter of a circle that is 792 cm. Find the ratio of the side of the square to the radius of the circle.
A rectangular park with length and breadth of 16m and 20m, is surrounded by a path of 6m wide. Find the area of the path.
If the ratio of areas of two circle is 9:25, then the ratio of their circumferences will be:
Cylinder radius = 7 cm, height = 12 cm. It is melted into cones of radius 3.5 cm, height 8 cm. Find number of cones.
Relevant for Exams:
