Answer:
0.043 seconds
2.7378×10⁻⁸ seconds
Step-by-step explanation:
In the question it is given each century adds 1 ms to a day due to the slowing rotation of the Earth
In 43 centuries the length of the first day of the year will be
43 × 1 = 43 ms = 0.043 seconds
1 ms = 1 century
1 century = 100 years × 365.25 days
⇒1 ms = 36525 days

Sum of the gain on the first day would be
0.043 + 2.7378×10⁻⁸ = 0.04300000273785 second
Sum of the gain on the second day would be
0.043 + 2.7378×10⁻⁸+2.7378×10⁻⁸ = 0.04300054757 seconds
The increase in each day would be 2.7378×10⁻⁸ seconds