1.3 Geometric sequences and seriesIB Maths: Applications and Interpretation SL: Mind map

Exam questions on 1.3 Geometric sequences and series

1. A geometric sequence has first term $u_1=4$ and common ratio $r=3$.
   Find the least value of $n$ for which $u_n>10\,000$.2 marks
2. A virus spreads so that the number of new cases each day is 1.5 times the number of new cases on the day before. On day 1 there are 40 new cases.
   Find the first day on which the number of new cases is greater than 1000.2 marks
3. A geometric sequence has $u_2=12$ and $u_5=96$.
   Find the common ratio $r$ and the first term $u_1$.3 marks