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(a) 5!*4! (for arranging the 5trees and 4 trees which are on opposite sides of the road)
(b) (4!*2! *3!*2!)/5!*4!
im not even sure if these answers are correct
(a) Simply 9! = 362880
(b) Regard the two trees as a unit. There are 7 locations available to place this unit. (Any two neighbouring slots can form a valid location but not on different sides.) 7 locations for 1 unit to fit in, that's 7P1.
Next, there are 7 slots left (9 minus 2) for the remaining 7 trees to fit in. This is 7P7.
In addition, in that unit, the 2 trees can be placed in different orders, so it's an extra 2P2.
Total number of ways is then 7P1 × 7P7 × 2P2 = 70560
(c) You can first plant the 2 magnolias, 1 on either side. So that is 4P1 × 5P1.
Then plant the remaining 7 trees in the 7 slots left. 7P7
It is notable that among the 7, 4 are of one species and 3 are of another. So the number should be divided by 4P4 then by 3P3.
Final answer is 4P1 × 5P1 × 7P7 / (4P4 × 3P3) = 700
I have a severe confusion in normal distribution and binomial distribution.. :'(
i mainly have problem identifying when to apply continuity in conversion from binomial to normal. and this is as i've figured out mainly because i cant seem to identify the questions in which the continuity correction is to be applied.. Can you Please PLEASE explain to me what type of question does the examiner give in which the continuity is to be applied and what type of question he gives when it doesnt has to be applied.. please explain the major differences between the two questions if possible with an example.. its maths p6 day after tomorrow and it would really mean alot if u could help me.. Thanks in advancee....
i mainly have problem identifying when to apply continuity in conversion from binomial to normal. and this is as i've figured out mainly because i cant seem to identify the questions in which the continuity correction is to be applied.. Can you Please PLEASE explain to me what type of question does the examiner give in which the continuity is to be applied and what type of question he gives when it doesnt has to be applied.. please explain the major differences between the two questions if possible with an example.. its maths p6 day after tomorrow and it would really mean alot if u could help me.. Thanks in advancee....