Question 59

Mathematics Sequence And Series Easy

If \( A_{1}, A_{2} \) be two \( A M \) 's and \( a \) and \( b \) , then \( \frac{A_{1}+A_{2}}{G_{1} G_{2}} \) is equal to

(A) \( \frac{a+b}{2 a b} \)
(B) \( \frac{2 a b}{a+b} \)
(C) \( \frac{a+b}{a b} \)
(D) \( \frac{a+b}{\sqrt{a b}} \)
✓ Correct Answer: Option C Verified Solution

📘 Step-by-Step Solution & Detailed Explanation:

As per question AP series will be $a, A_1, A_2, b$ $$d = \frac{b-a}{3}$$ $$A_1 = a + \frac{b-a}{3} = \frac{2a+b}{3}$$ $$A_2 = a + \frac{2(b-a)}{3} = \frac{a+2b}{3}$$ GP series will be $a, G_1, G_2, b$ $$r = \left(\frac{b}{a}\right)^{1/3}$$ $$G_1 = a\left(\frac{b}{a}\right)^{1/3} = b^{1/3}a^{2/3}$$ $$G_2 = a\left(\frac{b}{a}\right)^{2/3} = b^{2/3}a^{1/3}$$ Required ratio will be $\frac{A_1 + A_2}{G_1 G_2} = \frac{\frac{2a+b}{3} + \frac{a+2b}{3}}{a^{2/3}b^{1/3} a^{1/3}b^{2/3}} = \frac{\frac{3a+3b}{3}}{ab} = \frac{a+b}{ab}$

Practice Similar Sequence And Series Questions

Reinforce your conceptual grasp with related questions from CUET-MCA 2023:

Q71 The H.P. of two numbers is 4 and the arithmetic mean \( A \) and geometric...
Solve →
Q85 Given below are two statements: One is labeled as \(Assertion \ (A)\) and...
Solve →
Q14 The area of a rhombus is \( 120 ~cm 2 \) and length of its one diagonal in...
Solve →
Q24 If \( cot 2 45 -sin 2 45 =K sin 2 30 × tan 2 45 × sec 2 45 \) , then the...
Solve →
Q26 Given below are two statements: Statement I: If the roots of the quadratic...
Solve →
Full-Length Test Series

Prepare for CUET-MCA Under Real Exam Conditions

Take timed full-length mock tests with authentic question distributions, negative marking (+12/-3 in Math), and instant All India Rank calculation.

Start Free Mock Test Series →