Let the number ( 22 ) 2022   +   ( 2022 ) 22 leave the remainder α when divided by 3 and…

Let the number (22)2022 + (2022)22 leave the remainder α when divided by 3 and β when divided by 7. Then (α2 + β2 ) is equal to
  1. 20
  2. 13
  3. 5
  4. 10

Solution

Given that α be the remainder when 222022+202222 is divided by 3 and β be the remainder when the same is divided by 7.

222022+202222=21+12022+202222.

Here 202222 is divisible by 3 as 2022 is divisible by 3.

So on expanding 21+12022, we get

21+12022=C02022212022+C12022212021+......+C2022202212022

=332021×72022+C12022×32020×72021+......+1

=3k1+1

In this case the remainder is 1

Hence, α=1

Now, 222022+202222=21+12022+2023-122

Take 2023-122

2023-122=C022202322-C122202321+......+C2222-122

=7C02272128922-C12272028921+......+1

=7k2+1

21+12022+2023-122=7k1+1+7k2+1

=7μ+2

β=2.

Hence, α2+β2=12+22=5.

Therefore, the required answer is 5.

Asked in: JEE Main 2023 (10 Apr Shift 2)

Practice more Binomial Theorem questions on Aicharya