25 minutes
Given:
Question:
How long did Jenny read?
The Process:
Step-1: We need to calculate the time of texting a friend in minutes.
Recall that [tex]\boxed{1 \ hour = 60 \ minutes}[/tex]
Let us prepare a diagram for [tex]\boxed{60 \div 3 = 20 \ minutes}[/tex], that is [tex]\boxed{20}\boxed{20}\boxed{20} = 60 \ minutes[/tex].
[tex]\boxed{\frac{1}{3} \ hour = \ ? \ minutes}[/tex]
Since [tex]\boxed{ \ 1 \ unit = 20 \ minutes \ }[/tex], so Jenny spends 20 minutes of texting a friend.
Or, we can find out in the following way:
[tex]\boxed{= \frac{1}{3} \ hour \times 60 \ minutes}[/tex]
Therefore, [tex]\boxed{\boxed{ \ = 20 \ minutes \ }}[/tex]
Step-2: Jenny spends [tex]\frac{1}{4}[/tex] of the time brushing her teeth and putting on her pajamas.
Let us prepare a diagram for [tex]\boxed{60 \div 4 = 15 \ minutes}[/tex], that is [tex]\boxed{15}\boxed{15}\boxed{15}\boxed{15} = 60 \ minutes[/tex].
[tex]\boxed{\frac{1}{4} \ hour = \ ? \ minutes}[/tex]
Since [tex]\boxed{ \ 1 \ unit = 15 \ minutes \ }[/tex], so Jenny spends 15 minutes brushing her teeth and putting on her pajamas.
Or, we can find out in the following way:
[tex]\boxed{= \frac{1}{4} \ hour \times 60 \ minutes}[/tex]
Therefore, [tex]\boxed{\boxed{ \ 15 \ minutes \ }}[/tex]
Step-3: Let us calculate how long Jenny read for the rest of time.
[tex]\boxed{60 \ minutes - 20 \ minutes - 15 \ minutes }[/tex]
[tex]\boxed{\boxed{ \ = 25 \ minutes \ }}[/tex]
Thus, Jenny spent 25 minutes reading a book before its bedtime.
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Quick Steps:
Let us calculate how long Jenny read for the rest of time.
[tex]\boxed{ \ = \bigg(1 - \frac{1}{3} \bigg - \frac{1}{4} \bigg) \times 60 \ minutes \ }[/tex]
Least common multiple (LCM) for 3 and 4 are equal to 12.
[tex]\boxed{ \ = \bigg(\frac{12}{12} - \frac{4}{12} \bigg - \frac{3}{12} \bigg) \times 60 \ minutes \ }[/tex]
[tex]\boxed{ \ = \frac{5}{12} \times 60 \ minutes \ }[/tex]
We crossed out 12 and 60, i.e., [tex]\boxed{60 \div 12 = 5}[/tex]
[tex]\boxed{ \ = 5 \times 5 \ minutes \ }[/tex]
[tex]\boxed{\boxed{ \ 25 \ minutes \ }}[/tex]
Keywords: Jenny, has an hour, before, its bedtime, spends 1/3 of an hour, texting a friend, 1/4 of the time, brushing her teeth, putting on her pajamas, reading her book, 25 minutes, read
