Mathematics of investment by Altares, Priscilla S., Arce, Ma. Teresa B, Aquino, Abner A., CoPo, Antonio Roland I., Howe, Asuncion B., Laddaran, Angeline T., Mananquil, Claro T., Sy, Evangeline Agueda G., Tizon, Helen D., Villanueva, Antonio, Yao, Ana Maria S.D