maths problems

[anam]

1) five identical balls are merked with the numbers: 7, 3, 4, 2, 1 and are placed in a box. the balls are thoroughly mixed before three balls are drawn out all at one time from the box. A score is obtained by adding the numbers on the three balls drawn. find how many different scores are possible and the possible score.

2) a passenger train travelled at a speed of 72km/h. a man on the passenger train observed a goods train travelling at a speed of 54 km/h in the opposite direction. if the goods train passed him in 8 secs, find the length of the goods train.

 

[Nikesh]

Solution of Question 1)
is its answer 10.
I think its 10 because there are total 5 identical balls out of which we have to pick up 3 ball at once and get their sum.
For this order of balls do not matter at all as 123,213,321 gives the same sum. So we have to use the combination rule i.e.5Cr3 which gives the result as 10!!!!!!!!!! so their are total of 10 possible scores.
the scores would be as follows:
734 742
732 741
731 721
342 341
321
421



But i 2 got shocked in one step that 732 and 741 both gives the same sum although they form different number!!!!