JEE Main202227 Jul 2022Morning ShiftMathematicsBinomial TheoremActual
The remainder when 2021 2022 + 2022 2021 is divided by 7 is
Options
- A0
- B1
- C2
- D6
Correct answer
A. 0
Step-by-step solution
We know 2023 = 7 × 289 So 2021 2022 + 2022 2021 = 2023 - 2 2022 + 2023 - 1 2021 = 7 m 1 + 2 2022 + 7 m 2 + - 1 2021 = 7 m 1 + m 2 + 8 674 - 1 = 7 m 1 + m 2 + ( 7 + 1 ) 674 - 1 = 7 m 1 + m 2 + 7 m 3 + 1 - 1 = 7 m 1 + m 2 + m 3 This is a multiple of 7 Hence, remainder is 0