alleryStart learning →What is the common ratio of 5, 15, 45, 135?
- 3
- 10
- 9
- 5
Show answer and solution
Correct answer: A. 3
Dividing any term by the one before it, 15/5 = 45/15 = 3.
CA Foundation Number Series, Coding and Decoding — practice questions — page 2
Explore 67 free Number Series, Coding and Decoding questions in CA Foundation Quantitative Aptitude. Open each question or exercise to read its content, reference answers and available explanation.
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Showing questions 31–60 of 67.
What is the common ratio of 5, 15, 45, 135?Read the answer and worked solution →If F1 = F2 = 1, what is the 10th Fibonacci number?Read the answer and worked solution →After 34 and 55 in a Fibonacci-type series, the next term is?Read the answer and worked solution →Fibonacci numbers were first described in India by whom, about 200 BC?Read the answer and worked solution →The Fibonacci numbers are named after which mathematician?Read the answer and worked solution →Dividing consecutive Fibonacci numbers gives values close to which constant?Read the answer and worked solution →Find the odd one out: 16, 25, 36, 48, 49Read the answer and worked solution →Among 2, 3, 5, 9, 11, which number does not belong with the rest?Read the answer and worked solution →Which entry does not belong in 1, 3, 6, 10, 14, 15?Read the answer and worked solution →Spot the intruder among 13, 17, 19, 21 and 23.Read the answer and worked solution →Which of 121, 144, 169, 200 and 225 breaks the group?Read the answer and worked solution →Three of these numbers fit a rule, one does not: 2, 3, 5, 8, 13, 20. Which does not?Read the answer and worked solution →Which number is out of place in 3, 9, 27, 81, 243, 250?Read the answer and worked solution →One of 15, 25, 35, 45 and 49 differs from the others. Which?Read the answer and worked solution →Pick the number that does not fit with 1, 4, 9, 16, 24, 25.Read the answer and worked solution →Find the odd one out: ACE, BDF, CEG, DFH, EGHRead the answer and worked solution →Which of these is not a perfect square?Read the answer and worked solution →In a Caesar cipher with a left shift of 3, E becomes which letter?Read the answer and worked solution →Each letter is moved 3 places right in the alphabet. CAT becomes?Read the answer and worked solution →Each letter was moved 2 places right to make the code ECV. What was the word?Read the answer and worked solution →With A = 1, B = 2, C = 3 and so on, what is the sum of the letters in BAD?Read the answer and worked solution →With A = 1, B = 2 and so on to Z = 26, what is the letter sum of DOG?Read the answer and worked solution →If A = 26, B = 25, C = 24 and so on, what is the code for D?Read the answer and worked solution →If CAT is coded as DBU, how is DOG coded?Read the answer and worked solution →If each letter is replaced by the one before it, HELLO becomes?Read the answer and worked solution →If BOOK is written as KOOB, how is PEN written in the same code?Read the answer and worked solution →In the ROT13 system, which letter replaces A?Read the answer and worked solution →A Caesar cipher is a type of which kind of cipher?Read the answer and worked solution →The Caesar cipher takes its name from which Roman?Read the answer and worked solution →How secure is a Caesar cipher in modern practice?Read the answer and worked solution →
Worked practice questions
If F1 = F2 = 1, what is the 10th Fibonacci number?
- 34
- 55
- 45
- 89
Show answer and solution
Correct answer: B. 55
The sequence runs 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, so F10 = 55.
After 34 and 55 in a Fibonacci-type series, the next term is?
- 79
- 99
- 89
- 84
Show answer and solution
Correct answer: C. 89
Adding the previous two terms, 34 + 55 = 89.
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