Find the 10th and 12th term of the series 1, 3.5, 6, 8.5,...? And their ratio is?
Select the correct option
A) .98  B) 2.5  C) 1.21  D) 3.4  E) 2
common difference = d = 3.5 - 1= 
<gadget id="calculator">3.5 - 1</gadget>
<output>2.5</output>
2.5 ,, n= 10, a = first term = 1-----   By using arithmetic progression , t10 = a + (n-1)*d = 1 + (10-1)*2.5 = 1+22.5= 
<gadget id="calculator">1+22.5</gadget>
<output>23.5</output>
23.5 Also 12th term , t12= a + (n-1)*d = 1 + (12-1) * 2.5= 
<gadget id="calculator">1 + (12-1) * 2.5</gadget>
<output>28.5</output>
28.5   Ratio= t12/t10 = 28.5/23.5 = 1.21..... Ans - 1.21
<result>C</result>
Find the 10th and 12th term of the series 1, 3.5, 6, 8.5,...? And their ratio is?