passwella.
Menu

WAEC Mathematics 2017 Question 4

Question 4

Modular Arithmetic

Fig. 1 and Fig. 2 are the addition and multiplication tables respectively in modulo 5. Use these tables to solve the equation (n ⊗ 4) ⊕ 3 = 0(mod 5).

Diagram for this question
  1. A.1
  2. B.2
  3. C.3
  4. D.4
Show the answer and explanation

Answer: C (3)

Explanation

n ⊗ 4 must be 2 (since 2 ⊕ 3 = 0). From the multiplication table, 3 ⊗ 4 = 2, so n = 3.