English Math F2 and F3

Question1 a^6k^6 - 1
=(ak)^6 - 1
=[(ak)³]² - 1²
=[(ak)³+1] [(ak)³-1]
=[(ak)³+1³] [(ak)³-1³]
=(ak+1) [a²k²-ak+1] (ak-1) [a²k²+ak+1]



Question2 If the radius of a circle is reduced by 15%, find the percentage change in the
circle.

percentage change
=[2π(1-0.15)-2π]/2π*100%
=-15%



Question3 A charity organisation raises fund by selling raffle tickets. When compared with last year, the price of each ticket is increased by 15%, while the number of tickets sold is decreased by 6%. What is the percentage change in the fund raised in these two years?

percentage change
=[(1+15%)(1-6%)-1]/1*100%
=8.1%



Question4 If $70 000 invested at 6% p.a compounded monthly, find the compound interest after 8 months.

compound interest
=70 000(1+6%/12)^8-70 000
=$2849



Question5 If $8000 is deposited at 10% p.a compounded monthly, find the compound interest after 3 months.

compound interest
=8000(1+10%/12)^3-8000
=$201

2013-10-26 08:01:02 補充：
如果有嘢唔明，可以補充發問，我樂意回答^^