What is the last digit in 7^402 + 3^402

• Numbers

What is the last digit in 7⁴⁰² + 3⁴⁰²?

1. 0
2. 2
3. 4
4. 8

Answer

Last digit in 7⁴⁰² + 3⁴⁰² is the last digit in the sum of last digits in 7⁴⁰² and 3⁴⁰² respectively.

402 = (4×100) + 2

So, last digit in 7⁴⁰² is last digit in 7² and last digit in 3⁴⁰² is last digit in 3².

7² = 49 and 3² = 9

So, last digit in 7⁴⁰² and 3⁴⁰² is the last digit in the sum of last digits in 49 and 9.

Since, 9 + 9 = 18,

So, required last digit is 8.

The correct option is D.