Answer:
Your friend is 2.143 blocks from the restaurant.
You are 2.857 blocks from the restaurant.
Explanation:
Let t be the time both you and your friend take to walk to the restaurant.
The distance (m) from your building to the restaurant is your walking time t times your speed v1
[tex]s_1 = v_1t = 1.6t[/tex]
Similarly the distance (m) from your friend building to the restaurant:
[tex]s_2 = v_2t = 1.2t[/tex]
Let b be the length (in m) of a block, the total distance of 5 blocks is 5b
[tex]s_1 + s_2 = 5b[/tex]
[tex]1.6t + 1.2t = 5b[/tex]
[tex]2.8t = 5b[/tex]
[tex]t = 5b/2.8 = 25b/14[/tex]
[tex]s_2 = 1.2t = 1.2(25b/14) = 2.143b[/tex]
So your friend are 2.143b meters from the restaurant, since each block is b meters long, 2.143b meters would equals to 2.143b/b = 2.143 blocks. And you are 5 - 2.143 = 2.857 blocks from the restaurant.