answer this please

Question

john takes an hour to distribute newspaper in block of apartment while his friends takes 80 minutes to do the same work individually .If all they distribute newspaper in 2 such blocks of apartment ,how long would they take?

Answer 1

Think of this question in terms of speed like miles per hour. John's rate is 1 block per hour. His friends rate is 1 block per 80 minutes. First, you want to make both rates use the same units. You can multiply hours by 60 to get minutes. Now the two rates are:

1. John does 1 block/60 minutes
2. His friend does 1 block/80 minutes
3. Now we want to switch these speeds to the same denominator so we can add them. Multiply the numerator and denominator of his friend by 6/8 to get both speeds to be in terms of 60 minutes. Now:
4. John does 1 block/60 minutes
5. His friend does (6/8 blocks)/60 minutes
6. Now add their speeds and together, they do 14/8 blocks/60 minutes To find how long it would take for them to do 2 blocks,use the equation time = distance / rate so do 2/(14/8) to get 16/14 units of 60 minutes or 16/14 hours. This is equal to approximately 68.6 minutes.
7. Sorry about the formatting, the laTex is not working on Wyzant right now. Let me know if you have any questions!