A lighthouse flashes a beam of light once every 3/5 of a minute. How many times does it flash a beam of light in half an hour?

Total number of flash = 50 flash

Step-by-step explanation:

Given:

Time taken of a flash = 3/5 minute = 3/5 × 30 = 36 sec

Total time = 30 minute = 30 × 60= 1800 sec

Find:

Total number of flash in 30 minutes

Computation:

⇒ Total number of flash = Total time / Time taken of a flash

⇒ Total number of flash = 1800 / 36

⇒ Total number of flash = 50 flash

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.