SOLUTION: a person is walking with uniform speed. he increases his speed by 20% when he completes half the journey. the second half of the journey takes 30 minutes less than the first half.

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: a person is walking with uniform speed. he increases his speed by 20% when he completes half the journey. the second half of the journey takes 30 minutes less than the first half.       Log On


   

Question 449943: a person is walking with uniform speed. he increases his speed by 20% when he completes half the journey. the second half of the journey takes 30 minutes less than the first half. What is the time taken to cover both halves individually?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
1st half:
+d+=+r%2At+
2nd half:
+d+=+%28+r+%2B+.2r%29%2A%28t+-+30%29+
+r%2At+=+1.2%2Ar%2At+-+36r+
divide both sides by r
+t+=+1.2t+-+36+
+.2t+=+36+
+t+=+180+
The 1st half takes 3 hrs to cover
+t+-+30+=+150+
The 2nd half takes 2 and a half hours to cover