Target Exam

CUET

Subject

General Aptitude Test

Chapter

Numerical Ability

Topic

Number System

Question:

Match List-I with List-II

List-I

List-II

(A) Remainder when $17^{35234}$ is divided by 8

(I) 0

(B) Remainder when 4444 is divided by 9

(II) 1

(C) Unit's digit of $(34)^{15}+(34)^{16}$

(III) 2

(D) Unit digit of $7^4-9^3$

(IV) 7

Choose the correct answer from the options given below:

Options:

(A)-(II), (B)-(IV), (C)-(I), (D)-(III)

(A)-(I), (B)-(II), (C)-(III), (D)-(IV)

(A)-(II), (B)-(IV), (C)-(III), (D)-(I)

(A)-(IV), (B)-(II), (C)-(I), (D)-(III)

Correct Answer:

(A)-(II), (B)-(IV), (C)-(I), (D)-(III)

Explanation:

The correct answer is Option (1) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)

List-I

List-II

(A) Remainder when $17^{35234}$ is divided by 8

(II) 1

(B) Remainder when 4444 is divided by 9

(IV) 7

(C) Unit's digit of $(34)^{15}+(34)^{16}$

(I) 0

(D) Unit digit of $7^4-9^3$

(III) 2

(A) Remainder when $17^{35234}$ is divided by 8:

  • First, find the remainder of the base: $17 \div 8 = 2$ with a remainder of 1.
  • Using the property of remainders: $17^{n} \equiv 1^{n} \pmod{8}$.
  • Since $1^{35234} = 1$, the remainder is 1.
  • Match: (A) - (II)

(B) Remainder when 4444 is divided by 9:

  • To find the remainder when a number is divided by 9, we sum its digits: $4 + 4 + 4 + 4 = 16$.
  • Now, divide the sum by 9: $16 \div 9 = 1$ with a remainder of 7.
  • Match: (B) - (IV)

(C) Unit's digit of $(34)^{15} + (34)^{16}$:

  • We only need to look at the last digit, which is 4.
  • The cyclicity of 4 is: $4^1 = 4$, $4^2 = 16$ (ends in 6), $4^3 = 64$ (ends in 4).
    • $4^{\text{odd}}$ ends in 4.
    • $4^{\text{even}}$ ends in 6.
  • $(34)^{15}$ has an odd power, so its unit digit is 4.
  • $(34)^{16}$ has an even power, so its unit digit is 6.
  • Sum of unit digits: $4 + 6 = 10$. The unit digit of the result is 0.
  • Match: (C) - (I)

(D) Unit digit of $7^4 - 9^3$:

  • $7^4$: $7 \times 7 \times 7 \times 7 = 2401$. The unit digit is 1.
  • $9^3$: $9 \times 9 \times 9 = 729$. The unit digit is 9.
  • Subtraction: $1 - 9 ⇒11 - 9$ (borrowing from the next place value) = 2.
  • Match: (D) - (III)