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Find the sum of 5+8+aa+....+24

A) 1500
B) 1800
C) 2100
D) 2400

Correct Answer:

A) 1500

Description for Correct answer:
Here a=5, d=8-5=3, n=24

\( \Large S_{n}=\frac{n}{2}\left[ 2a+ \left(n-1\right)d \right] \)

= \( \Large \frac{24}{2}\left[ 2 \times 5+ \left(24-1\right)5 \right] \)

= \( \Large 12\left[ 10+115 \right] \)

=\( \Large 12 \times 125 = 1500 \)

Part of solved Factorisation questions and answers : >> Elementary Mathematics >> Factorisation

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