S Shoom Member Joined Aug 26, 2008 Messages 694 Gender Undisclosed HSC N/A Oct 20, 2008 #1 lucia earns 25000, her wage increases by 5% every year find wage after 6 years The common ratiio of a geometic series is 4 and the sum of first 5 terms is 3069 find the first term, SHOW WORKING PLEASE.
lucia earns 25000, her wage increases by 5% every year find wage after 6 years The common ratiio of a geometic series is 4 and the sum of first 5 terms is 3069 find the first term, SHOW WORKING PLEASE.
A Azreil Member Joined May 28, 2007 Messages 274 Gender Female HSC 2008 Oct 20, 2008 #2 25000 * 1.05^6 = $33502.39 Sum = a(r^n - 1)/(r-1) 3069=a(4^5-1)/(4-1) a=9 1st term = 9
S Shoom Member Joined Aug 26, 2008 Messages 694 Gender Undisclosed HSC N/A Oct 20, 2008 #3 Why is it (r) 1.05 and not 0.05
A Azreil Member Joined May 28, 2007 Messages 274 Gender Female HSC 2008 Oct 20, 2008 #4 r = 1 + R R = percentage given -- that's just how I remember it. If you think about it though, multiplying by 0.05 would give a DECREASING answer whereas her salary is increasing.
r = 1 + R R = percentage given -- that's just how I remember it. If you think about it though, multiplying by 0.05 would give a DECREASING answer whereas her salary is increasing.
