The distinct letters from the word MEMORIAL are used to create set Z, such that Z = {M, E, O, R, I, A, L}. The letters from the word DAY are used to create set Y, such that Y = {D, A, Y}. If set X is...
According to “A History of Valentine’s Day Cards in America” by T.M. Wilson, in 1847 Esther Howland was the first to mass-produce Valentine’s Day cards. She made them out of lace, paint and expensive...