SOLUTION: The ratio of the prices of the keyboard and the monitor is 1 : 4. If the price of the monitor increases by 20% and the ratio decreases by 5%, what is the percentage increase/decrea

Algebra ->  Average -> SOLUTION: The ratio of the prices of the keyboard and the monitor is 1 : 4. If the price of the monitor increases by 20% and the ratio decreases by 5%, what is the percentage increase/decrea      Log On


   

Question 860107: The ratio of the prices of the keyboard and the monitor is 1 : 4. If the price of the monitor increases by 20% and the ratio decreases by 5%, what is the percentage increase/decrease in the price of the keyboard ?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+1%2F4+-+.05%2A%28+1%2F4+%29+=+%28+1+%2B+x+%29+%2F+%28+4+%2B+.2+%29+
+.95%2A%28+1%2F4%29+=+%28+1+%2B+x+%29+%2F+4.2+
+.95+=+%28+1+%2B+x+%29%2A%28+2%2F2.1+%29+
+1.995+=+2+%2B+2x+
+2x+=+-.005+
+x+=+-.0025+
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The new ratio is:
+%28+1+%2B+x+%29+%2F+4.2+=+.9975+%2F+4.2+
The % decrease in the price of the keyboard is:
+.0025 = .25%
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check:
+.95%2A%28+1%2F4%29+=+%28+1+%2B+x+%29+%2F+4.2+
+.95%2A%28+1%2F4%29+=+%28+1+-+.0025+%29+%2F+4.2+
+.95%2A.25+=+.9975+%2F+4.2+
+.9975+=+.95%2A.25%2A4.2+
+.9975+=+.9975+
OK