Q2. There are 16 empty boxes in the figure. (a) To fill in any 4 boxes with black colour, how many different patterns can be formed?(i've solved this already )ans:1820(b) Now we have 8 different colour pens without black colour. To fill in any 5 remaining boxes in the pattern obtained in (a) with different colours, how many different patterns can be formed? ans:9686476800
Q3. A school organized a table-tennis tournament. Any two players must play against each other. However, a player was quit after playing 3 matches and another player was absent from two matches, therefore these two players did not play against each other. If a total of 57 matches were played finally, how many players were there originally? ans: 12
may anyone give me a hand ? :)
Q4. It is given that 2 x 3 x 5 x 7 x 11 x 13 =30030. How many positive factors of 30030 are multiples of 3? ans:32
更新1:
求solution
