Form 4 maths ( plz help~~~~)

1. The value of a new car is $500,000. The value $V of the car depreciates according to the formula below:
V = a * 3^bt
Where a and b are constants and t is the time taken in months.
(a) Find the constant a.
(b) After 2 years, the value of the car is $300,000, find the value of b, correct to 3 significant figures.
(c) Find the value of the car after 10 months correct to the nearest dollar.
(d) For how long will the value of the car be half of the original?
(e) If the car is resold at $100,000, what is the maximum age of the car?
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2. When A56CE(16) is converted into a denary number, how many digits are there?
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3. Let 101010(2) = P (10) and 1010000(2) = Q(10). How many prime numbers are there bettween P and Q?
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