2021 · Q99
What is the unit digit in the expansion of 67³²?
Elementary MathematicsNumber System
- A1
- B3
- C7
- D9
Explanation
The unit digits of powers of 7 cycle every 4 (7, 9, 3, 1). Since 32 = 4·8, 7³² ends in 1, so 67³² ends in 1. Hence option A.
What is the unit digit in the expansion of 67³²?
Explanation
The unit digits of powers of 7 cycle every 4 (7, 9, 3, 1). Since 32 = 4·8, 7³² ends in 1, so 67³² ends in 1. Hence option A.