Given: 26th January 2019 was a Saturday
Required: Day of the week on 15th August 2015
To find the day, calculate the total number of days between 15th August 2015 and 26th January 2019.
Remaining days in August 2015 (after 15th): 31−15=16 days
September 2015: 30 days
October 2015: 31 days
November 2015: 30 days
December 2015: 31 days
Days from August to December 2015: 16+30+31+30+31=138 days
Complete years:
Year 2016 (leap year): 366 days
Year 2017: 365 days
Year 2018: 365 days
Total for complete years: 366+365+365=1096 days
January 2019 (up to 26th): 26 days
Total days from 15th August 2015 to 26th January 2019:
138+1096+26=1260 days
To find the day of the week, calculate 1260mod7:
1260=7×180
1260mod7=0
Since the remainder is 0, going back 1260 days (exactly 180 weeks) from Saturday gives Saturday.
Therefore, 15th August 2015 was a Saturday.
The answer is Option 1: Saturday.