সমাধান - জ্যামিতিক ধারা

সিরিজের সাধারণ রূপ খুঁজে পেতে, প্রথম পদ: $$a=60$$ এবং সাধারণ অনুপাত: $$r=1.15$$ জ্যামিতিক সিরিজের সূত্রে প্লাগ করুন:

$$a_1=60$$

$$a_2=a_1·r^{n-1}=60\cdot {1.15}^{2-1}=60\cdot {1.15}^1=60\cdot 1.15=69$$

$$a_3=a_1·r^{n-1}=60\cdot {1.15}^{3-1}=60\cdot {1.15}^2=60\cdot 1.3224999999999998=79.35$$

$$a_4=a_1·r^{n-1}=60\cdot {1.15}^{4-1}=60\cdot {1.15}^3=60\cdot 1.5208749999999998=91.25249999999998$$

$$a_5=a_1·r^{n-1}=60\cdot {1.15}^{5-1}=60\cdot {1.15}^4=60\cdot 1.7490062499999994=104.94037499999996$$

$$a_6=a_1·r^{n-1}=60\cdot {1.15}^{6-1}=60\cdot {1.15}^5=60\cdot 2.0113571874999994=120.68143124999996$$

$$a_7=a_1·r^{n-1}=60\cdot {1.15}^{7-1}=60\cdot {1.15}^6=60\cdot 2.313060765624999=138.78364593749995$$

$$a_8=a_1·r^{n-1}=60\cdot {1.15}^{8-1}=60\cdot {1.15}^7=60\cdot 2.6600198804687487=159.6011928281249$$

$$a_9=a_1·r^{n-1}=60\cdot {1.15}^{9-1}=60\cdot {1.15}^8=60\cdot 3.0590228625390607=183.54137175234365$$

$$a_{10}=a_1·r^{n-1}=60\cdot {1.15}^{10-1}=60\cdot {1.15}^9=60\cdot 3.5178762919199196=211.07257751519518$$