If the square of the 7th term of an arithmetic progression with positive common difference equals the product of the 3rd and 17th terms, then the ratio of the first term to the common difference is

A) 2 : 3

B) 3 : 2

C) 3 : 4

D) 4 : 3

Option (A)

From CAT 2017 – Quantitative Aptitude – Modern Maths – Progressions, we can see that,

(a+6d)^2 = (a+2d)(a+16d)

a^2 + 12 ad + 36d^2 = a^2 + 18 ad + 32d^2

Since, d is positive,

We get the ratio of a:d = 2:3

Option (A)

Quantitative Aptitude – Modern Maths – Progressions – Q1: If a1 = 1/(2*5), a2 = 1/(5*8), a3 = 1/(8*11),â€¦â€¦, then a1 + a2 +â€¦â€¦..+ a100 is

Quantitative Aptitude – Modern Maths – Progressions – Q2: An infinite geometric progression a1, a2, a3,â€¦ has the property that an = 3(a(n+ l) + a(n+2) +â€¦.) for every n â‰¥ 1. If the sum a1 + a2 + a3 +â€¦â€¦. = 32, then a5 is

Quantitative Aptitude – Modern Maths – Progressions – Q3: Let a1, a2, a3, a4, a5 be a sequence of five consecutive odd numbers. Consider a new sequence of five consecutive even numbers ending with 2a3. If the sum of the numbers in the new sequence is 450, then a5 is

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Quantitative Aptitude – Modern Maths – P&C – Q1: How many four digit numbers, which are divisible by 6, can be formed using the digits 0, 2, 3, 4, 6, such that no digit is used more than once and 0 does not occur in the left-most position?

Quantitative Aptitude – Modern Maths – P&C – Q2: In how many ways can 8 identical pens be distributed among Amal, Bimal, and Kamal so that Amal gets at least 1 pen, Bimal gets at least 2 pens, and Kamal gets at least 3 pens?

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