Maths qusetions!! (Hard)

2009-04-14 2:08 pm

Please Work these following questions out
I am stuck=(
Show your working please=]

1) A large tub of popcorn costs ￡3.80 and holds 280g.
A regular tub of popcorns costs ￡3.50 and holds 175g.

Rob says that 200g Large tub is the better value for money.
Linda says that 175g Regular tub is the better value for money.

-Who is correct?
-Explain the reasons for your answer.You must show all your working.

2) This item appeared in a newspaper

Cows produce 3% more milk
A farmer found that when his cow listened to classical music the milk it produced increased by 3%.
This increase of 3% represented 0.72 Litres if milk

-Calculate the amount of milk produced by the cow when it litened to classical music.

3) PQR is a right-angled triangle.

PR= 6cm
QR= 4cm

-Work out the length og PQ
-Give your answer in 3 significant figyres.

Thanks very much=D

回答 (1)

bean_bottom_2

2009-04-14 3:03 pm

✔ 最佳答案

Q1:
280g for ￡3.8 so each gram is ￡0.01357
175g for ￡3.5 so each gram is ￡0.02
Therefore the large tub is cheaper (ie 175g for ￡3.5 is more expensive).

Q2:
0.72L is 3% so that total before the increase is 100% = 24L
After the increase, the total will be 24.72L

Q3:
I am assuming angle PQR is the right angle (from your notation). This implies 62 = 42 + (PQ)2
==> 36 = 16 + (PQ)2
==> 20 = (PQ)2
==> PQ = 4.472

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