Alrighty then.
q8. Point K lies on the line y=-4x and you're given the x value which is -2, so you sub that into the equation to get the y value.
y=-4(-2) = 8
So K is (-2, 8)
q13. The boat drops a crab pot every 10min. There are 60min in an hour. So the boat drops 6pots an hour. So, for it to drop 96 pots that would take 96/6=16hours
q16. Two whole numbers which multiply to give 231, and neither of them is one. If you look at the number, the digit sum is 6 which is a multiple of 3, so the entire number is divisible by 3. Then you just divide it by 3 to give 3 and 77 [you could also rearrange it to give 21 and 11, or 33 and 7 or whatever]
q18. (3× 10^4)× (2× 10^–6). You just multiply the 2 and 3 at the front together to give 6, and use your index laws to multiply the 10^4 and 10^-6 to give 10^-2. Which gives 6x0.01, which is 0.06
q81a] Stella is a netball player. The number of goals she scored in her first seven games was 3, 4, 5, 5, 6, 8, 9. The mode is 5- mode is the most frequently occuring score.
b] Of her first 7 games, she scored 6goals in one of them, 8 in another and 9 in a third. Therefore she has a 3/7 probability of scoring at least 6goals in her next match.
c] To calculate the mean, add all the scores together and divide by the number of scores. Which is 40/7
d] After her next 3 games, for her to have a mean of 7 she'd need to bring up her total number of goals to 70 over 10 games. So she'd have to score 10 goals in each of the next 3 games, and that's the only way you can do it while keeping a range of 7.
q82a] 60L at $1.24 a litre. So she pays 60x1.24 = $74.40
b] Hers is $1.24 a litre, his is $1.16 a litre. The difference and thus the saving is 8cents per litre.
c] She uses 15L over 100km. 20 is a fifth of 100, so to travel 20 she'll use a fifth of what she uses to travel 100. Which is 1/5 x 15 = 3L
d] The saving she'd make on buying 60L at his station is 60x0.08 = $4.80
The return trip to his station and back would be 40km, which uses 6L [as in c]] which unfortunately for her would cost more than she's saving even if she bought it at his station. Silly woman.
Hope that helps :]
