question:A can do a piece of work in 14 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 18
(B) 77
(C) 66
(D) 55
(E) 14
answer:(E)
Stream of consciousness:8/14 + 6/x = 1
X = 14 days

question:Ravi can do a piece of work in 30 days while Prakash can do it in 40 days. In how many days will they finish it together?
Options:
(A) 17 1/7 days
(B) 17 1/8 days
(C) 17 5/7 days
(D) 17 3/7 days
(E) 13 1/7 days
answer:(A)
Stream of consciousness:1/30 + 1/40 = 7/120
120/7 = 17 1/7 days

question:A train crosses a platform of 150 m in 15 sec, same train crosses another platform of length 250 m in 20 sec. then find the length of the train?
Options:
(A) 150
(B) 78
(C) 268
(D) 268
(E) 298
answer:
(A)
Stream of consciousness:Length of the train be 'X'
X + 150/15 = X + 250/20
4X + 600 = 3X + 750
X = 150m ]