Maria spent 3 hours writing adresses for 50 party invitiations. At this rate, how long will it take Maria to write adresses for 90 invitation
3 / 50 = x /90 cross-multiply
3 * 90 = x * 50 divide both sides by 50
3 * 90 / 50 = x
270 / 50 = x
27 / 5 = x
5 2/5 hrs = x = 5.4 hrs = 5 hr 24 min
