View in English View in Hindi 
An aeroplane flying at a height of 300 m above the ground passes vertically above another plane at an instant when the angles of elevation of the two planes from the same point on the ground are 60º and 45º respectively. What is the height of the lower plane from the ground? 
A) 100√3 m
B) 100/√3 m
C) 50/√3 m
D) 150(√3 +1) m
Correct Answer : 100√3 m Explanation : Let the height of the lower plane from the ground be h m and PA = x Now, in BAP, Now In APC From Eqs. (i) and (ii), we get 
Post/View Answer
Post comment
Cancel
Thanks for your comment.!
Write a comment(Click here) ...

View in English View in Hindi 
A boy is flying a kite. The string of the kite makes an angle of 60^{o} with the ground. If the height of the kite is 32 m, find the length (in meters) of the string. 
A) 64
B) 32/√3
C) 32√3
D) 64/√3
Correct Answer : 64/√3 Explanation : Sin q = Perpendicular/Hypotenuse Hence, the length (in meters) of the string L= 64/√3

A pole of height h = 60 ft has a shadow of length l= 60 ft at a particular instant of time. Find the angle of elevation (in degrees) of the sun at this point of time. 
A) 30
B) 45
C) 60
D) 40
Correct Answer : 45 Explanation : let, hight of the pole = BC and length of shadow is = AB 
A person standing on bank of the river observes that the angle subtended by a tree on the opposite bank is 60° and when he retires 40m from the bank, he finds the angle of elevation as 30°. Then the breadth of the river is 
A) 40m
B) 20m
C) 22m
D) 35m
Correct Answer : 20m Explanation :
tan 60 =h/x tan 30 = h/ 40+x using eq(1) 
Two men on one sides of a building of height 25 m notice the angle of elevation of the top of the building to be 45^{o} and 60^{o} respectively. Find the distance (in meters) between the two men. 
A) 32(1+ (1/√3))
B) 15/√3
C) 25(1(1/√3))
D) 25√3
Correct Answer : 25(1(1/√3)) Explanation :

From the top of a building 90 m high, the angles of depression of the top and the bottom of a tree are 30º and 45º respectively. What is the height of the tree? 
A) 30√3 m
B) 9030√3 m
C) 90+30√3 m
D) 60+30√3 m
Correct Answer : 9030√3 m Explanation : Let AB and CD be the building and tree respectively. Again, in AEC Hence, Height of tree = CD = BE = ABAE = 9030√3 m 