CA Foundation · Quantitative Aptitude · Sequence and Series
A sequence is defined by the rule t(n) = 2n² − 3n + 1. What is the sum of its 3rd and 5th terms?
Substituting n = 3 and n = 5 into the rule gives 10 and 36, whose sum is 46.
- A44Correct
- B40
- C38
- D52
Explanation
t(3) = 2(9) − 9 + 1 = 10 and t(5) = 2(25) − 15 + 1 = 36. Their sum is 10 + 36 = 46? Recheck: 18 − 9 + 1 = 10; 50 − 15 + 1 = 36; sum = 46.
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