DIRECTIONS : Problems based on Area.
| 9. |
A rectangular plot measuring 90 metres by 50 metres is to be enclosed by wire fencing. If the poles of the fence are kept 5 metres apart, how many poles will be needed? |
| |
A. 55 |
| |
B. 56 |
| |
C. 57 |
| |
D. 58 |
| Solution |
| Perimeter of the plot | = 2 ( 90 + 50 ) |
| = 280 m. |
| Number of poles | = (280 / 5) |
| = 56 m. |
|
| 10. |
The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and breadth is increased by 5 cm, the area of the rectangle is increased by 75 sq.cm. Find the length of the rectangle? |
| |
A. 10 cm |
| |
B. 20 cm |
| |
C. 30 cm |
| |
D. 40 cm |
| Solution |
| Let the breadth = x | Then length =2x |
| = [(2x-5)(x+5)-2x ] x [x=75] |
| x =20. |
| Length of the rectangle=20cm. |
|
| 11. |
A room 5m 55cm long and 3m 74cm broad is to be paved with square tiles. Find the least number of square tiles required to cover the floor? |
| |
A. 176 |
| |
B. 175 |
| |
C. 185 |
| |
D. 188 |
| Solution |
| Area of the room | = (544 x 374)cm ² |
| Size of largest square tile | = H.C.F of 544 & 374cm |
| = 34 cm |
| Area of 1 tile | = (34 x 34)cm² |
| Number of tiles required | = [544 x 374 / 34 x 34] |
| = 176. |
|
| 12. |
The base of a parallelogram is twice its height. If the area of the parallelogram is 72 sq.cm. Find its height? |
| |
A. 3 cm |
| |
B. 6 cm |
| |
C. 7 cm |
| |
D. 9 cm |
| Solution |
| Let the height of the parallelogram be x cm.Then base |
| = (2x) cm |
| =2x² = 72 |
| x²=36 |
| x = 6. |
|