manalq8 wrote:
The 19th of September 1987 was a Saturday. If 1988 was a leap-year, what day of the week was the 21st of September 1990?
A. Monday
B. Tuesday
C. Wednesday
D. Thursday
E. Friday
There are 365 days in an ordinary year and 366 days in a leap-year.
365 divided by 7 (a week period) yields a remainder of 1, thus the same date after an ordinary year would fall on the next day of a week;
366 divided by 7 (a week period) yields a remainder of 2, thus the same date after a leap-year would fall two days after in a week;
Thus 3 years, 1988, 1989 and 1990, will accumulate 2+1+1=4 days, plus 2 days of difference between 19th and 21st, which gives total of 6 days of difference (6 days shift). Thus, 21st of September 1990 was Saturday+6 days=Friday.
Answer: E.
: Wouldn’t GMAC have to provide how many days are in a leap year? All the information needed to answer any of the questions is always included on the exam, with no outside knowledge needed.