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by armaan700+ » Tue Jan 26, 2010 2:57 am
If a motorist had driven 1 hour longer on a certain day and at an average rate of 5 miles per hours faster, he would have covered 70 more miles than he actually did. How many more miles would he have covered than he actually did if he had driven 2 hours longer and at an average rate of 10 miles per our faster on that day?
a. 100
b 120
c 140
d 150
e 160
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Source: — Problem Solving |

by ajith » Tue Jan 26, 2010 4:14 am
armaan700+ wrote:If a motorist had driven 1 hour longer on a certain day and at an average rate of 5 miles per hours faster, he would have covered 70 more miles than he actually did. How many more miles would he have covered than he actually did if he had driven 2 hours longer and at an average rate of 10 miles per our faster on that day?
a. 100
b 120
c 140
d 150
e 160
Say h is the original no of hours and r is the original speed at which motorist was travelling

(h+1)(r+5) = h*r + 70

=> hr + 5h + r + 5 = hr +70
=> 5h+r = 65 ---- (1)


Now we want to know (h+2)(r+10) - hr

= hr + 2r + 10h + 20 -hr
= 2(5h+r)+20
= 130+20 =150
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by thephoenix » Tue Jan 26, 2010 4:54 am
where v is equal to the per hour rate:

v+5 = 70
v = 65

2(65 +10) = 150
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