A. 173 m
B. 200 m
C. 273 m
D. 300 m
Let AB be the lighthouse and C and D be the
positions of the ships. Then,
AB = 100 m, ∠ACB = 300 and ∠ADB = 45°.
AB/AC = tan 30° = 1/√3
AC = AB X √3 = 100√3 m.
AB/AD = tan 45° = 1 ⇒ AD = AB = 100 m.
CD = (AC + AD) = (100√3 + 100) m
= 100 (√3 +1) m = (100 X 2.73) m = 273 m.
Related Mcqs:
- The top of a 15 metre high tower makes an angle of elevation of 60° with the bottom of an electric pole and angle of elevation of 30° with the top of the pole. What is the height of the electric pole ?
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C. 173 m
D. 200 m - Find the area of trapezium whose parallel sides are 20 cm and 18 cm long, and the distance between them is 15 cm.
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B. 275 cm2
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D. 315 cm2 - The angle of elevation of a ladder leaning against a wall is 60° and the foot of the ladder is 4.6 m away from the wall. The length of the ladder is :_________?
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A. 20 km
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D. 10 km - P and Q started a business investing Rs. 85,000 and Rs. 15,000 respectively. In what ratio the profit earned after 2 years be divided between P and Q respectively?
A. 3:4
B. 3:5
C. 15:23
D. 17:23
E. None of these - An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in 5/3 hours, it must travel at a speed of:_________?
A. 660 km/hr
B. 680 km/hr
C. 700 km/hr
D. 720 km/hr - In two successive years, 100 and 75 students of a school appeared at the final examination. Respectively 75 % and 60 % of them passed. The average rate of pass is:_________?
A. 68 4/7 %
B. 78 %
C. 80 %
D. 80 4/7 % - If the height of a pole is 2√3 metres and the length of its shadow is 2 metres, find the angle of elevation of the sun.
A. 50°
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