2012 AMC 12A Problems and Solution
Problem 1
A bug crawls along a number line, starting at
. It
crawls to
, then
turns around
and crawls to
. How many units does the bug crawl altogether?
Solution
Crawling from -2 to -6 takes it a distance of 4 units. Crawling from -6 to 5 takes it
a distance of 11 units. Add 4 and 11 to get
Problem 2
Cagney can frost a cupcake every
seconds and Lacey can frost a cupcake every
seconds. Working together, how many cupcakes can they frost in
minutes?
Solution
Cagney can frost one in 20 seconds, and Lacey
can frost one in 30 seconds. Working
together, they can frost one in
seconds. In 300 seconds (5
minutes), they can frost
.
Problem 3
A box
centim
eters high,
centim
eters wide, and
centim
eters long can hold
grams of clay. A second box with twice the height, three tim
es the width, and the
sam
e length as the first box can hold
gram
s of clay. What is
?