question_answer

DIRECTIONS: Read the passage(s) given below and answer the questions that follow. Passage ? 2 At an international Airport, planes take off from four different runways at 4, 8, 12 and 15 minute interval At 9 a.m., planes took off from all the four run way simultaneously but Reema has missed her flight due to traffic jam. When will four planes take off together again?

A)  11 : 00 a.m.       

B)              10 : 00 a.m.

C)  12 : 00 noon      

D)              11 : 30 a.m. 

Correct Answer: A

Solution :

     L.C.M. of 4, 8, 12 and 15 L.C.M. \[=2\times 2\times 2\times 3\times 5=120\] Thus, four planes take off together again after 120 minute i.e. after 2 hour. i.e. 11 a.m.