Quantitative Aptitude – Modern Maths - Sequence and Series – Let t1, t2,… be real numbers
Slot -2 – Quantitative Aptitude – Modern Maths - Sequence and Series – Let t1, t2,… be real numbers
Let t1, t2,… be real numbers such that t1+t2+…+tn = 2n2+9n+13, for every positive integer n ≥ 2. If tk=103, then k equals?
Answer: 24
Solution:
Given, t(base1)+t(base2)+…+t(base n) = 2n^2+9n+13
So t(base1) + t(base2) = 2×2^2+9×2+13=39
t(base1) + t(base2) + t(base3) = 2×3^2+9×3+13=58 means t(base 3) = 58 –
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Quantitative Aptitude – Modern Maths - Sequence and Series – The value of the sum 7 x 11
Slot -2 – Quantitative Aptitude – Modern Maths - Sequence and Series – The value of the sum 7 x 11
The value of the sum 7 x 11 + 11 x 15 + 15 x 19 + ...+ 95 x 99 is?
a) 80707
b) 80730
c) 80773
d) 80751
Answer: a) 80707
Solution: 7 x 11 + 11 x 15 + 15 x 19 + ...+ 95 x 99
nth term of series = {4(n+1)-1}×{ 4 (n+1)+3}=16n^2+16+32n+8n+8-
3=16n^2+40n+21
Thus 7 x 11 + 11 x 15 + 15 x 19 + ...+ 95 x 99 = ∑ Tn=∑ (
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