Paper 1 October/November 2011 MATHEMATICS (9709/12) A Levels
لطفا برای اطمینان از عملکرد و تجربه بهتر از مرورگرهای مدرن و به روز مانند کروم یا فایرفاکس استفاده کنید.

a) A geometric progression has a third term of 20 and a sum to infinity which is three times the first term. Find the first term.
b) An arithmetic progression is such that the eighth term is three times the third term. Show that the sum of the first eight terms is four times the sum of the first four terms.