What is the unit (last) digit of 7²³?
Correct answer: B. 3
The units digits of powers of 7 repeat every 4: 7, 9, 3, 1. 23 ÷ 4 leaves remainder 3, so the units digit is the third in the cycle: 3.
hard
Answer and explanation
The correct answer is B. 3
The units digits of powers of 7 repeat every 4: 7, 9, 3, 1. 23 ÷ 4 leaves remainder 3, so the units digit is the third in the cycle: 3.
Topic: LCM, HCF and Number System MCQs · Subject: Mathematics