Two ships are sailing in the sea on the two sides of a lighthouse. The angle of elevation of the top of the lighthouse is observed from the ships are 30Â° and 60Â° respectively. If the lighthouse is 189 m high, the distance between the two ships is:
OPtion
1) 416.47 m
2) 436.47 m
3) 426.47 m
4) 446.47 m
5) 466.47 m
6) 456.47 m
7) 476.47 m
8) 486.47 m
9) 496.47 m
10)None of these
Solution
Let AB be the lighthouse where A is the bottom point of light house and C and D be the positions of the ships.
Then, AB = 189 m, Angle ACB = 30Â° and angle ADB = 60Â°.
AB/AC = tan 30Â° = 1/sq root(3)
=> AC = AB * sq root(3) = 189*3^(1/2)
AB/AD = tan 60Â° = 1/sq root(3)
=> AD = AB*1/sq root(3) = 189/*3^(1/2) = 63*3^(1/2)
Two ships are sailing in the sea on the two sides of a lighthouse. The angle of elevation of the top of the lighthouse is observed from the ships are 30Â° and 45Â° respectively. If the lighthouse is 169 m high, the distance between the two ships is:
OPtion
1) 460.72 m
2) 468.72 m
3) 463.72 m
4) 464.72 m
5) 461.72 m
6) 465.72 m
7) 467.72 m
8) 469.72 m
9) 462.72 m
10)None of these
Solution
Let AB be the lighthouse where A is the bottom point of light house and C and D be the positions of the ships.
Then, AB = 169 m, Angle ACB = 30Â° and angle ADB = 45Â°.
AB/AC = tan 30Â° = 1/sq root(3)
=> AC = AB * sq root(3) = 169*3^(1/2)
A boatman goes 3 km against the current of the stream in 2 hour and goes 1.5 kms along the current in 30 minutes. How long will it take to go 12 km in stationary water?
A father said to his son, "I was as old as you are at the present at the time of your birth". If the father's age is
74 years now, what would be the son's age after thirteen years?
Let the sons current age be x
So fathers age x years back when son was born => 74-x = x
Solving we get x = 37
13 Years later son's age = 37+13 = 50 years
I got placed in Infosys as well as L &T InfoTech
thanks a lot to m4maths
Rupa Muddaraboina1 year ago
Hi friends I am attend the tcs pool campus held on mar 2nd 2016 and the results are released I am clear the written test thanks to m4 maths and give me suggestions to clear the interview round friends.
Avinash1 year ago
Search for this page
m4maths 11. in 6 years, raj’s father will be twice raj’s a 57,93,121,124,133 how to find the sequence of 1, 9, 54, 270,....... http://m4maths.com maths trick what is the next number of the following sequence