15. One card is drawn at random from a well shuffled deck of 52 cards. In which of the following cases are the events E and F independent ?
(i) E : 'the card drawn is a spade'
F : 'the card drawn is an ace'
(ii) E : 'the card drawn is black'
F : 'the card drawn is a king'
(iii) E : 'the card drawn is a king or queen'
F : 'the card drawn is a queen or jack'.