Work out the answers to the following problems．
1．An express train leaves London for Manchester at 9：15 in the morning．It travels at an average of 165 k．p．h．A slow train leaves Manchester for London at 10：30 the same morning．It travels at an average speed of 90 k．p．h．It's 395 km from London to Manchester．Which train is nearer London when they meet，the train from London or the train from Manchester？
2．There are fifty socks，twenty-five black and twenty-five red，in a drawer．It's dark and you want a pair of socks the same colour．What's the smallest number of socks you must take out to make sure you've got a pair of socks the same colour？
3．A man is looking at a photograph．He says，‘This person's father is my father's son．But I haven't got any brothers or sisters．’What relation is the man to the person in the photograph？
James from Oxford Intensive English Course
