need help with 2005 sc for maths plzzz (1 Viewer)

[palozrule4lyf]

i realy need help with these questions and can u plz put the answers in detail

50
71
73
74
75
80
81
82
83
84
http://www.boardofstudies.nsw.edu.au/schoolcertificate/sc2005/pdf_doc/mathematics_sctest_05.pdf
thnks!!!!!!!!!!!!!!

 

[supre]

i realy need help with these questions and can u plz put the answers in detail

50
71
73
74
75
80
81
82
83
84

50. scale factor basically just means that the pic shown on the paper has been tripled from its actual size. so measure the size of the bug using a ruler then divide the number by 3.
71. i used the probability table to work this answer out and got 12 possible ways.(D)
73. there are 6 faces on the cube and one cube has been halfed so the surface area increased by 2/6 which is 1/3. (C)
74. isabella's brothers age 2 years ago=x-2 and isabella has three times old as her brother so it is 3(x-2) 3x-6 (this is isabella's age 2 years ago) so isabella's age now= 3x-6+2= 3x-4 (B)