SOLUTION: A certain highway has a 2% grade. How many feet does it rise in a horizontal distance of 1 mile? (1 mile = 5280feet.)

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Question 1009161: A certain highway has a 2% grade. How many feet does it rise in a horizontal distance of 1 mile? (1 mile = 5280feet.)
Answer by farohw(175) About Me  (Show Source):
You can put this solution on YOUR website!

Convert 2% to 2/100 then set up your equation:

2%2F100+=+y%2F5280

Before solving for y, you may choose to reduce accordingly:

1%2F50+=+y%2F5280

By cross multiplication, 50y+=+5280

Divide both sides by 50 to obtain a value for y,

50y%2F50+=+5280%2F50 --> y+=+528%2F5 or 105.6.

The highway rises 105.6 ft in a horizontal distance of one mile.

Verify:
2%2F100+=+y%2F5280 where y = 105.6

2%2F100+=+105.6%2F5280

2%2F100+=+1%2F50 which is also 2% is true.