a2zinterviews

24.	A housing society has been allotted a square piece of land measuring 2550.25 sq.m. What is the side of the plot?
	A.  50.25 m
	B.  50.5 m
	C.  50.65 m
	D.  50.85

Solution

Side = √2550.25 = √255025 / 100 = 505 / 10 = 50.5 m.

25.	A park square in shape has a 3 metre wide road inside it running along its sides. The area occupied by the road is 1764 square metres. What is the perimeter along the outer edge of the road?
	A.  576 metres
	B.  589 metres
	C.  600 metres
	D.  700 metres

Solution

Let the length of the outer edges be x metres. Then, length of the inner edge = ( x - 6)m. ∴ x2 - (x-6)2 = 1764 ‹=› x2-(x2-12x+36)= 1764 ‹=›12x = 1800 ‹=›x = 150. ∴ Required perimeter = (4x)m ‹=› (4 x 150)m = 600m.

26.	A can go round a circular path 8 times in 40 minutes. If the diameter of the circle is increased to 10 times the original diameter, then the time required by A to go round the new path once, travelling at the same speed as before is
	A.  20 min
	B.  35 min
	C.  50 min
	D.  70 min

Solution

Let original diameter be d metres. Then, its circumference = (Πd)metres. Time taken to cover (8Πd)m = 40 min. New diameter = (10d)m. Then, its circumference = (Π x 10d)m. Time taken to go round it once ‹=› [40 / 8Πd x 10Πd]m ‹=›50 min.