Enginpasa1 wrote:Youseff lives x blocks from his office. It takes him 1 minute per block to walk towork and 20 second per block to ride his bike to work. It is takes him exactly 10 minutes more to walk to work than to ride his bike to work, then x equals?

a.4
b.7
c.10
d.15
e.20


qa is d

My approach: I added the rates which came to 4blocks per minute but was not able to set up the proper equation ot finish the question. I tried to plug it into DRT but I got confused. I can easily finish advanced (two worker) at same time questions. But I get stuck on these!

this question is also a perfect candidate for plugging in the answer choices and working backwards.

try the middle choice (c) first:
if it's ten blocks, then it takes ten minutes to walk the distance, and 10 x (1/3) = 3 1/3 minutes to bike it. (note that i'm using 20 seconds = 1/3 minute)
that's not a large enough difference, and the smaller distances would lead to even smaller differences. so, a, b, and c are all gone.

try (d):
if it's fifteen blocks, then it takes 15 minutes to walk the distance, and 15 x (1/3) = 5 minutes to bike it. so, there you go: the difference is ten minutes.

sweetness