Coding & Decoding
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Q1.The positions of the first and sixth digits in the number 5109238674 are interchanged. Similarly, the positions of second and seventh digits are interchanged and so on. Which one of the following will be the third digit from the right end after the rearrangement?
Correct Answer: B
Swapping digits 1↔6, 2↔7, 3↔8, 4↔9, 5↔10 in '5109238674' and identifying the third digit from the right gives 0.
Q2.If BAT is coded as 283, CAT is coded as 383 and ARE is coded as 801, then the code for BETTER is:
Correct Answer: C
Correct Answer: 123301.
Q3.If BOY is coded as 539 and GIRL is coded as 8627 then how would you encode GLORY?
Correct Answer: D
From 'BOY' (539) and 'GIRL' (8627), we get individual letter mappings: G=8, L=7, O=3, R=2, Y=9. Combining these, GLORY is coded as 87329.
Q4.If SELFLESS is coded as SSEFLES, how is BROKER written in that code?
Correct Answer: B
Split word into halves: BRO and KER. Reverse each half: ORB and REK. Place second reversed half first: REKORB.
Q5.Solve the cryptarithm: C + CA = ATT (representing digits, CA is 2-digit, ATT is 3-digit). What is the value of C?
Correct Answer: C
Equation: C + 10C + A = 100A + 11T => 11C - 99A = 11T => C - 9A = T. Since C, A, T are digits and A cannot be 0, A must be 1. C - 9 = T => C must be 9 and T = 0. (9 + 91 = 100).
Q6.In a certain code MISSIONS is written as MSIISNOS. How is INTERNET written in that code?
Correct Answer: C
First and last letters stay in place. Middle letters are swapped in pairs: NT → TN, ER → RE, NE → EN. This yields ITENNRTE.
Q7.If 7+2-1 = H and 22+8-6 = W. What is the letter for 11 + 6 - 1 = ?
Correct Answer: C
7+2-1 = 8 (8th letter is H). 11+6-1 = 16 (16th letter is P).
Q8.If FEED is coded as 4339, then what will be the code for DEEF?
Correct Answer: C
Matching: F=4, E=3, E=3, D=9. Therefore, DEEF = 9334.
Q9.If 2 x 2 = 44, 3 x 2 = 94, then what does 9 x 4 equal?
Correct Answer: C
The rule is concatenating squares: A × B = (A²)(B²). For 2×2 => 4 and 4 => 44. For 3×2 => 9 and 4 => 94. For 9×4 => 9²=81 and 4²=16 => 8116.
Q10.If: 22 × 33 = 4499, 33 × 44 = 991616, Then, 44 × 55 = ?
Correct Answer: A
The pattern squares each double digit separately: 22 * 33 -> 2^2=4, 2^2=4, 3^2=9, 3^2=9 -> 4499. For 44 * 55, we do: 4^2=16, 4^2=16, 5^2=25, 5^2=25 -> 16162525.
Q11.1 = 0, 2 = 8, 3 = 16, 4 = ?
Correct Answer: B
The formula is: n * 8 - 8. For n = 1: 1*8 - 8 = 0. For n = 2: 2*8 - 8 = 8. For n = 3: 3*8 - 8 = 16. For n = 4: 4*8 - 8 = 24.
Q12.If DEEF → 4556, then 6554 = ?
Correct Answer: B
Since D=4, E=5, E=5, F=6, reversing the digits to 6554 maps to: 6=F, 5=E, 5=E, 4=D, which spells FEED.
Q13.Rearrange the word AKLCIHA?
Correct Answer: A
The letters AKLCIHA can be rearranged to spell KALACHI, which is a city/village.
Q14.Rearrange the word DFFADLOI
Correct Answer: C
The letters DFFADLOI rearrange to form the word DAFFODIL, which is a type of flower.
Q15.If 3=6, 4=8, and 5=10, then 6 = ?
Correct Answer: B
Each number on the left is multiplied by 2 to get the value on the right: 3*2=6, 4*2=8, 5*2=10. Therefore, 6 * 2 = 12.
Q16.If A= 2, B= 4, C= 6, then what E =?
Correct Answer: C
Each letter is coded as twice its alphabetical position: A (1*2=2), B (2*2=4), C (3*2=6). Since E is the 5th letter, its code is: 5 * 2 = 10.
Q17.If CAT = 24 and DOG = 26, then FOX = ?
Correct Answer: A
Sum of alphabetical positions of letters: C(3) + A(1) + T(20) = 24. DOG = D(4) + O(15) + G(7) = 26. FOX = F(6) + O(15) + X(24) = 45.
Q18.If A + H2 = 7, then what is Z – O?
Correct Answer: C
Alphabet positions: Z = 26, O = 15. Therefore, Z - O = 26 - 15 = 11.
Q19.IF FELLOW IS CODED AS 465531 THEN ELLOW IS CODED AS?
Correct Answer: C
Letter coding: F=4, E=6, L=5, O=3, W=1. Replacing the letters in ELLOW yields 65531.
Q20.IF LAME IS CODED AS: 3425 , COOK=4006 , TEST=8598 then what is the code for : 2098?
Correct Answer: B
Decoded letters: 2=M, 0=O, 9=S, 8=T. The code 2098 represents the word MOST.