2009_10B_Worksheets.pdf - Each morning of her five-day...

Each morning of her five-day workweek, Jane bought
either a 50-cent muffin or a 75-cent bagel. Her total
cost for the week was a whole number of dollars. How
many bagels did she buy?
(A) 1 (B) 2 (C) 3 (D) 4 (E) 5
2009 AMC 10 B, Problem #1 —
2009 AMC 12 B, Problem #1 —
“Make a table for the cost of the muffins and bagels.”
Difficulty: Medium-easy
NCTM Standard: Number and Operations Standard: compute fluently and make reasonable
estimates.
Mathworld.com Classification: Number Theory > Arithmetic > General Arithmetic >
Arithmetic

Which of the following is equal to
1
3
-
1
4
1
2
-
1
3
?
(A)
1
4
(B)
1
3
(C)
1
2
(D)
2
3
(E)
3
4
2009 AMC 10 B, Problem #2 —
“The least common multiple of 2, 3, and 4 is 12.”
Solution
Answer (C): The least common multiple of 2, 3, and 4 is 12, and
1
3
-
1
4
1
2
-
1
3
·
12
12
=
4 - 3
6 - 4
=
1
2
.
Difficulty: Easy
NCTM Standard: Number and Operations Standard: judge the effects of such operations as
multiplication, division, and computing powers and roots on the magnitudes of quantities.
Mathworld.com Classification: Number Theory > Number Theoretic Functions > Least
Common Multiple > Least Common Multiple

Paula the painter had just enough paint for 30
identically sized rooms. Unfortunately, on the way
to work, three cans of paint fell off her truck, so she
had only enough paint for 25 rooms. How many cans
of paint did she use for the 25 rooms?
Difficulty: Medium-easy
NCTM Standard: Algorithm Standard: use symbolic algebra to represent and explain
mathematical relationships.
Mathworld.com Classification: Number Theory > Arithmetic > Fractions > Ratio

A rectangular yard contains two flower beds in the
shape of congruent isosceles right triangles. The
remainder of the yard has a trapezoidal shape, as
shown. The parallel sides of the trapezoid have lengths
15 and 25 meters. What fraction of the yard is
occupied by the flower beds?