I was solving Arithmetic from Manhattan 5 lb. there I got 1 question wrong Q15
I tried to calculate the number of years from the date May 30, 1917, to May 15, 1996, with the help of the formula used to find the sum of intervals = Last term (1996) - First term (1917) + 1
Can someone please explain to me why we are not supposed to add 1 here?
You should include the + 1. When you are trying to find the length of an interval (inclusive), your formula is right. Last term - First term + 1.
The solution here should be B > A. Quantity A and B has an equal number of full years. But May 30 till Dec 31 + Jan 1 till May 15 is less number of days than May 15 till Dec 31 + Jan 1 till May 30. About 30 days difference.
Explanation:
Quantity A:
May 30, 1917 - May 15, 1996
Full years: 1918 to 1995
n = 1995 - 1918 + 1 = 78 years
Quantity B:
May 15, 1912 - May 30, 1991
Full years: 1913 to 1990
n = 1990 - 1913 + 1 = 78 years
The remaining days of the year make the 30-day difference.
The only other consideration here is the leap year concept. Quantity A and B shared a lot of leap years (1920 - 1988). But quantity A has more leap years (1992 and 1996) while quantity B has only 1916. But this is not enough to make a difference
