April has 30 days in a month. So, to find the remaining days left in the month, subtract 30-11=18. So, from April 11 to 30, Millie's guarantee is 18 days old. To find the remaining days left in the guarantee, subtract 50-18=32. So there are 32 days left in the guarantee. Now, there are 31 days in May, so the guarantee will alst all through May and one day intoJune. So then guarantee will end June 1st