If the 1st day of a leap year is Saturday, then what day lies on 4th…

The correct answer is Option (1) → Saturday

Given:

• Leap year → February has 29 days
• 1st January = Saturday
• We need the day on 4th March

Step 1: Count days in January and February

• January → 31 days → remaining days after 1st Jan = 30 days
• February → 29 days in a leap year
• Total days from 1st Jan to 3rd March:

$\text{Days from 1 Jan to 3 Mar} = 31 + 29 + 3 - 1 - 31?$

Better: Count days from 1 Jan to 3 Mar

• January: 31 days → 1 Jan is Saturday → 31 Jan → day?
• Days of week advance by $31 \mod 7 = 3$
• 1 Jan = Saturday → 31 Jan = Saturday + 3 = Tuesday
• February: 29 days → days advance by $29 \mod 7 = 1$
• 1 Feb = Wednesday → 29 Feb = Wednesday + 1 -1? careful

Better: Count total days from 1 Jan to 4 Mar

• January: 31 days
• February: 29 days
• March: 4 days

Total days = 31 + 29 + 4 = 64 days

• Day of week formula:

$\text{Day on 4 Mar} = \text{Day on 1 Jan} + (64-1) \mod 7$

$64-1 = 63 \text{ days after 1 Jan}$

$63 \mod 7 = 0$

• 1 Jan = Saturday → 63 days later = same day = Saturday