wally gets £5 pocket money he puts it the bank for a year and earns interest of 5% how much money...
Post on 04-Jan-2016
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Wally gets £5 pocket money
He puts it the bank for a year and earns
interest of 5%
How much money does he have by the end of
the year?
£5 X 1.05
£5.05
Wally wants to buy a CD for £10
He has £8 in the bank
If interest rates are 7%, how long
will he need to save for until he can afford the
CD?
£8(1.07)x=£10
We could try and solve this be trail and error……
If x is 5 (5 years) we will have £11.22
Too much……if x is 4 years, we will have £10.50
Nearly…….if x is 3.5 years, we will have £10.13...
……or…..we can use logs………this is A Level
Maths!!£8(1.07)x=£10
(1.07)x=1.25
XLog101.07=Log101.25
X=3.3 years
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