A man usually rides his bike $9$ kilometers per hour, yet the wind slows him to $6.76$ kilometers for $26$ minutes and $5.55$ for $10$; how long until he gets home $11.54$ kilometers away? (This was a math question in a book of poetry I'm reading called Inside Out & Back Again.
I was just curious to see if anyone knew how to solve this, or has read the book.)
In order to calculate the time it took, multiply $6.76$ by $26/60$. This is due to the formula d=rt. Then add that result to ${5*5.55}/10$. Then, subtract that result from 11.54.
= $11.54-3.85433333333$
=$9.53566666667$
Now, divide it by the regular speed of 9 km/hr.
= $1.05951851852$ hours.
Multiply the decimal part by 60.
=$1$ hour $3.571$ minutes.
Multiply the decimal part again by 60.
=$1$ hour $3$ minutes $34$ seconds.