maths problem

chaz121

can someone please tell me how to do 2016 ordinary level maths paper one question 7 I haven't a clue!!

X6.430macman

8000 divife by100 multiply by 2=160
8160=244.8. (Divide by 100multiply by 3 this time)

8160+244.8=8404.8
8404.8+420.24=8825.04. Divide by 100multiply by 5 this time.

That's just for option one..hope this helps, come back If you want more guidance

rainbowtrout

The question about Paul putting money in the bank?

Part (a) with the three different interest rates is just:

8000 x 1.02 = 8160 ( end of year 1)
8160 x 1.03 = 8404.80 (end of year 2)
8404.80 x1.05 = 8825.04 (end of year 3)


Part (b) is compound interest

The formula is

Principal x (compound interest)^no of years

So 8000 x 1.037^3 = 8921.26 after 3 years



Part (c) give a reason for picking option 1 or 2

Opt 1: might want to take the money out after a year or two.
Opt 2: Provides the most interest so he will have more money


part (d) What rate of compound interest would give 9000 from his 8000 after 3 years.

You have to use the compound interest formula here and work backwards.

8000(comp. int)^3 = 9000


Divide across by 8000:

(Compound inter)^3 = 9000/8000 = 9/8

Get the cube root of both sides:
(Compound interest) = Cube root of (9/8) = 1.04


1 represents the full amount of money and the .04 the interest

Compound interest rate = 4%