MATHEMATICS
JAMB 2015 - Question 8
Mathematics 2015 JAMB Past Questions - Question 8: Find the sum of the first 11 terms of an A.P with first term 2 and the common difference 3.
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Correct Answer
A
Explanation
a=2 ,d=3 n=11Sn=n/2<2a+(n-1)d>Sn=11/2<2*2+(11-1)3>Sn=11/2<34>Sn=187The sum of the first n terms of an arithmetic progression (A.P.) can be found using the formula:Sn = n/2 * (2a + (n-1)d)Where:Sn = sum of the first n termsn = number of termsa = first termd = common differenceIn this case:n = 11 (the number of terms)a = 2 (the first term)d = 3 (the common difference)Now, we can substitute these values into the formula:Sn = 11/2 * (2*2 + (11-1)*3) = 11/2 * (4 + 10*3) = 11/2 * (4 + 30) = 11/2 * 34 = 187Therefore, the sum of the first 11 terms of the given arithmetic progression is 187.

