Difference between revisions of "2008 AMC 10B Problems/Problem 18"
Donotnomath (talk | contribs) (→Solution 1) |
Donotnomath (talk | contribs) (Explained that solution is B.) |
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==Solution 1== | ==Solution 1== | ||
Let <math>x</math> be the number of bricks in the chimney. Using <math>d=vt</math>, we get | Let <math>x</math> be the number of bricks in the chimney. Using <math>d=vt</math>, we get | ||
− | <math>x = (x/9 + x/10 - 10)\cdot(5)</math>. Solving for <math>x</math>, we get <math>\boxed{900} | + | <math>x = (x/9 + x/10 - 10)\cdot(5)</math>. Solving for <math>x</math>, we get <math>\boxed{900} \Rightarrow B</math>. |
==See also== | ==See also== | ||
{{AMC10 box|year=2008|ab=B|num-b=17|num-a=19}} | {{AMC10 box|year=2008|ab=B|num-b=17|num-a=19}} | ||
{{MAA Notice}} | {{MAA Notice}} |
Revision as of 03:54, 7 February 2018
Problem
Bricklayer Brenda would take nine hours to build a chimney alone, and bricklayer Brandon would take hours to build it alone. When they work together, they talk a lot, and their combined output decreases by
bricks per hour. Working together, they build the chimney in
hours. How many bricks are in the chimney?
Solution 1
Let be the number of bricks in the chimney. Using
, we get
. Solving for
, we get
.
See also
2008 AMC 10B (Problems • Answer Key • Resources) | ||
Preceded by Problem 17 |
Followed by Problem 19 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
All AMC 10 Problems and Solutions |
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