Question

Jaciee‘s mum says she has an hour before bed. Jenny Spends one third of the hour texting a Friend and one fourth of the hour to brushing her teeth and putting on pyjamas The rest of the time she read her book. How many minutes did Jaciee read

Answer 1

Explanation:

1 hour = 60 minutes

1/3 × 60 minutes = 20 minutes texting a friend.

1/4 × 60 minutes = 15 minutes brushing and pyjamas.

the remaining time for reading we can get in 2 ways :

1. 60 - 20 - 15 = 25 minutes reading

2. via the fractions

1/1 is the whole hour

1/1 - 1/3 - 1/4

to make this calculation, we need to bring all fractions to the same denominator.

the smallest number (LCM - least common multiple) that can be divided by 1, 3 and 4 is 12

1/1 × 12/12 = 12/12

1/3 × 4/4 = 4/12

1/4 × 3/3 = 3/12

so,

12/12 - 4/12 - 3/12 = 5/12

5/12 × 60 minutes = 5× 60/12 = 5×5 = 25 minutes reading.