Maths

Question

17.Last week,the exchange rate of Australian dollars to Hong Kong dollars was
AUS $1=HK$5.This week is AUS$1=$4.5.
a)Find the percentage decrease of the exchange of Australian dollars to Hong Kong dollars.
b)Daniel has AUS $1 000.If he wants to get more Hong Kong dollars,shoud he exchange the money last week or this week?What is the difference between the two?

Answer 1

a) percentage decrease
= - [ (4.5 - 5 ) / 5 x 100%]
= - [-0.5 / 5 x 100%]
= - [ - 10 %]
= 10%
B)
He should exchange last week.
the difference between the two weeks
= (1000 x 5) - (1000 x 4 . 5)
= 5000 - 4500
= HK $ 500