Since 2004, the amount of money spent at restaurants in a certain country has increased at a rate of 7% each year. In 2004, about $290 billion was spent at restaurants. If the trend continues, about how much will be spent at restaurants in 2018?
+526 In 2004 = $290 billion
In 2005 \(=(1+{7\over 100})*290\)
\(=310.3\)
In 2006 \(={107\over 100}×310.3\)
\(=332.02\)
In 2007 \(={107\over 100}×332.021\)
\(=355.26\)
... and so on
As you might have observed the above series forms a GP with
1st term a1 = 290 and common ratio r = 10.7
In order to find amount of money in 2018 (14 yrs later), we've to find the 15th term i.e. a15
⇒ \({a}_{15}= a × r^{14}\)
\(=290 × (10.7)^{14}\)
\(=$ 74777490355836152.54\) billion (approx.)
~Hope you got it :)
