Question

Nyoko needs to be at school at 7:45 AM. It takes her 15 minutes to walk to school, 5/12 hour to eat breakfast, 0.7 hour to get dressed, and 0.15 hour to shower. At what time should Nyoko get up to be at school 5 minutes early?

Answer 1

So, she wants to be at school at 7.40 (5 mins early)

she needs:

15 mins
5/12 hours (which is $\frac{5}{12} = \frac{25}{60}$, so 25 mins

so far: 40 mins

then 0.7 and 0.15: we can add those, since they're in decimals: 0.85.

how many minutes is this?

$\frac{85}{100} *60= \frac{85}{10} *6=\frac{85}{5} *3=\frac{13}{1} *3=39$

so 39 mins.

together with the previous 40, it's 79 minutes, which is 1 hour and 19 minutes: so she needs to wake up 1 hour and 19 minutes before 7.40 , which is

6.21!