Additional Mathematics 0606 / Series / 3.473.47: GP with S3=17.5S_3=17.5S3=17.5 and S∞=20S_\infty=20S∞=200606/21/O/N/22 — Question 7 · 6 marksMark as done · Save for later · Show all solutionsThe sum of the first three terms of a GP is 17.517.517.5 and S∞=20S_{\infty}=20S∞=20. Find the first term and common ratio.[6]▸ Answer▸ Official mark scheme← 3.45: GP fifteenth term and sum near infinity3.48: Triangle with surds; GP terms →