Total amount of time that Jenny has before bed time is 1 hour.
Jenny spends 1/3 of the hour texting a friend and 1/4 of the time brushing her teeth and putting on her pajamas. This means that total time that she has already spent is
1/3 + 1/4 = 7/12
If she spends the rest of the time reading her book, then the number of minutes that she spent reading her book would be
