SOLUTION: If Gina leaves now and drives 66 km/h she will reach Alton just in time for her appointment. On the other hand, if she has lunch first and leaves in 40 minutes, she will have to d

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: If Gina leaves now and drives 66 km/h she will reach Alton just in time for her appointment. On the other hand, if she has lunch first and leaves in 40 minutes, she will have to d      Log On

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Question 514905: If Gina leaves now and drives 66 km/h she will reach Alton just in time for her appointment. On the other hand, if she has lunch first and leaves in 40 minutes, she will have to drive 90km/h to make her appointment. How far away is Alton?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +t+ = the time in hours for her to make the
appointment if she drives at 66 km/hr
Let d = the distance to Alton
given:
+d+=+66t+
Going the same distance in in +40%2F60+ hrs less time
+d+=+90%2A%28+t+-+2%2F3+%29+
By substitution
+66t+=+90%2A%28+t+-+2%2F3+%29+
+66t+=+90t+-+60+
+24t+=+60+
+t+=+2.5+
and
+d+=+66t+
+d+=+66%2A2.5+
+d+=+165+
check answer:
+d+=+90%2A%28+t+-+2%2F3+%29+
+d+=+90%2A%28+5%2F2+-+2%2F3+%29+
+d+=+90%2A%28+15%2F6+-+4%2F6+%29+
+d+=+90%2A%2811%2F6%29+
+d+=+15%2A11+
+d+=+165+
Alton is 165 km away