^ Challenge 51. Heart Rates R ecom m ended h e a rt rates during exercise vary with age an d physical
condition. For a healthy p erso n doing m o d erate to intense exercise, such as hiking,
th e inequality 0.5(220 — a) < R < 0.9(220 - a) gives a target range for th e h e a rt
rate R (in beats p er m inute), b ase d on age a (in years).
a. W hat is th e target range for h e a rt rates for a p erso n 15 years old?
b. How old is a person w hose target range is b etw een 99 an d 178.2 beats
per m inute?- Chem ist ry M atter is in a liquid state w h e n its tem p eratu re is betw een its m elting
p o in t an d its boiling point. The m elting p o in t of th e elem en t m ercury is —38.87°C,
an d its boiling p o in t is 356.58°C. W hat is th e range of tem p eratu res in degrees
F ahrenheit for w hich m ercury is not in a liquid state? [Hint: C = | ( F - 32))
Express th e range as a n inequality a n d in interval notation.
^SAT/ACTSt a n d a r d i ze d Test Pr ep
- A taxi traveled 5 m i to John’s hom e a n d th e n drove him to the airp o rt 10 m i away.
W hich inequality represents the possible distances d of th e taxi from th e airport
w hen it started traveling tow ard John’s hom e?
C§>5 < 10 C D 5 < d < 15 ©0<rf<5 CD0<d<10 - A stu d en t m u st ea rn at least 24 credits in high school in order to graduate. W hich
inequality or graph does NOT describe this situation?
C D c < 24 C D 24 < c
Short
ResponseCD c > 24 CD-+- H h
-6 0 6 12 18 24 30 36 42- The C ounty W ater D e p artm en t charges a m onthly
adm inistration fee of $10.40 plus $.0059 for each gallon of w ater used, u p to, b u t
n o t including, 7500 gal. W hat are th e m in im u m a n d m axim um n u m b ers of gallons
of w ater u sed by custom ers w hose m onthly charge is at least $35 b u t no m ore th a n
$50? Express am o u n ts to th e n ea rest gallon.
r
Mixed Review
Let A = {1,3,5,7}, let B = {4, 8 ,12}, and let the universal set be
U= {1,2, 3, 4, 5, 7,8,12,15}.- W hat are th e subsets of A? 57. W hat is B"?
Solve each inequality.- 5 < 6 b + 3 60. 12n < 3n + 27
Get Read y! To p r e p a r e f o r Le sso n 3 - 7 , d o Ex e r c i se s 6 2 - 6 4.
Complete each statement with < , = , or >.- 13 — 7 1 4 63. I—5| + 2 6
Se e Lesso n 3- 5.- Is B' a subset of A?
Se e Lesso n 3- 4.- 2 + 4r>5(r- 1)
Se e Lesso n 1- 5.
64. |e -2 ± | 3§206 Chapter 3 Solving Inequalities
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