What was the day of the week on 2nd January 2010, if it was Sunday on 1st January 2006?

Given that 1st January 2006 was a Sunday, we need to find the day on 2nd January 2010.

The total time span needs to be calculated from 1st January 2006 to 2nd January 2010.

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Counting the number of days in each year:

Year 2006: 365 days (not a leap year)

Year 2007: 365 days (not a leap year)

Year 2008: 366 days (leap year, divisible by 4)

Year 2009: 365 days (not a leap year)

From 1st January 2010 to 2nd January 2010: 1 day

Total days $= 365 + 365 + 366 + 365 + 1$

Total days $= 1462$

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To find the day of the week, we calculate the number of complete weeks and remaining days:

$1462 \div 7 = 208$ remainder $6$

This means $1462 = 7 \times 208 + 6$

The remainder is 6 days.

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Starting from Sunday (1st January 2006) and moving forward 6 days:

Sunday $\rightarrow$ Monday $\rightarrow$ Tuesday $\rightarrow$ Wednesday $\rightarrow$ Thursday $\rightarrow$ Friday $\rightarrow$ Saturday

Therefore, 2nd January 2010 was a Saturday.

The correct answer is Option 1: Saturday.