# Maths

• Oct 2nd 2012, 09:37 AM
Spixol123
Maths
Hi,

For each Australia dollar, Amy receives 80 United States cents, I.e $A1 = US80c. She wants$US600 for a trip, how much should she receive in Australian dollars?

A)$480 B)$800 C)$750 (D)$720
• Oct 2nd 2012, 09:43 AM
MarkFL
Re: Maths
For each Australian dollar, Amy receives 4/5 U.S. dollars. Letting x be the number of Australian dollars, we can multiply this by 4/5 and equate to 600 to find the number of Australian dollars that is equivalent to 600 U.S. dollars.

$\displaystyle \frac{4}{5}\cdot x=600$

Now solve for x.
• Oct 2nd 2012, 09:50 AM
Spixol123
Re: Maths
what the best way of finding X? guess? trial and error??
• Oct 2nd 2012, 09:52 AM
MarkFL
Re: Maths
No, solve the equation. If you multiply both sides by 5/4, you will be left with x on the left, and on the right you have 5/4 times 600, which is the answer to the question.
• Oct 2nd 2012, 09:57 AM
Spixol123
Re: Maths
Thanks the only way i could figure out doing is multiplying A) B) C) D) until it gave me 600.