In an examination, a student was asked to find (3/14) of a certain number. By mistake he found (3/4) of it.His answer was 150 more than the correct answer.The given number is:

a) 180

b) 240

c) 280

d) 290

One year ago a father was four times as old as his son.In six year times, his age exceeds twice his son’s  age by nine years. Ratio of their ages is :

a) 13 : 4

b) 12 : 5

c) 11 : 3

d) 9 : 5