ESTUDYR
CST 222 MATH UPDATED EXAM WITH MOST TESTED QUESTIONS AND
ANSWERS | GRADED A+ | ASSURED SUCCESS WITH DETAILED
RATIONALES
28) What is always true about the sum of the interior angles of a triangle?
A. It equals 90°
B. It equals 270°
C. It depends on side length
D. It equals 180°
Rationale: Any triangle’s interior angles sum to a straight angle, which is 180°.
29) If the angles of a triangle are in a ratio a:b:ca:b:ca:b:c, which equation correctly finds xxx
to determine the angles ax,bx,cxax, bx, cxax,bx,cx?
A. ax+bx+cx=360ax+bx+cx=360ax+bx+cx=360
B. x(a+b+c)=90x(a+b+c)=90x(a+b+c)=90
C. ax+bx+cx=180ax+bx+cx=180ax+bx+cx=180 (equivalently
x(a+b+c)=180x(a+b+c)=180x(a+b+c)=180)
D. a+b+c=xa+b+c=xa+b+c=x
Rationale: Triangle interior angles sum to 180°, so x(a+b+c)=180x(a+b+c)=180x(a+b+c)=180.
30) Two whole numbers AAA and BBB have LCM 180 and GCF 12. Which value could be
A+BA+BA+B?
A. 72
B. 84
C. 96
D. 108
Rationale: A valid pair is A=36A=36A=36 and B=60B=60B=60.
gcd(36,60)=12\gcd(36,60)=12gcd(36,60)=12,
lcm(36,60)=180\mathrm{lcm}(36,60)=180lcm(36,60)=180, and 36+60=9636+60=9636+60=96.
, ESTUDYR
FRACTIONS AND MIXED NUMBERS
31) When subtracting mixed numbers with like denominators, if the minuend’s fractional
numerator is smaller than the subtrahend’s, what should you do?
A. Subtract anyway and keep the negative fraction
B. Multiply denominators
C. Regroup/borrow from the whole number OR convert to improper fractions, then subtract
D. Add the fractions first
Rationale: You must borrow 1 whole (convert to equivalent fraction) or use improper fractions
to subtract correctly.
RATES, PERCENT, AND WORD PROBLEMS
32) A vehicle travels for RRR hours at 65 mph. If it gets 24 mpg, what expression gives gallons
used?
A. 2465R\frac{24}{65R}65R24
B. 6524R\frac{65}{24R}24R65
C. 24(65R)24(65R)24(65R)
D. 65R24\frac{65R}{24}2465R
Rationale: Distance =65R=65R=65R miles. Gallons
=milesmpg=65R24=\frac{\text{miles}}{\text{mpg}}=\frac{65R}{24}=mpgmiles=2465R.
33) A TV price xxx is increased by 25% then discounted by 35% later. What is the final price
expression?
A. (1.25)(1.35)x(1.25)(1.35)x(1.25)(1.35)x
B. (0.75)(0.65)x(0.75)(0.65)x(0.75)(0.65)x
C. (1.35)(0.75)x(1.35)(0.75)x(1.35)(0.75)x
D. (1.25)(0.65)x(1.25)(0.65)x(1.25)(0.65)x
Rationale: Increase 25% ⇒ multiply by 1.25. Decrease 35% ⇒ multiply by 0.65.
34) A person earns $1200. They spend 14\frac{1}{4}41 on rent. From the remainder, they
spend 20% on utilities and 25% on food. How much money is left?
CST 222 MATH UPDATED EXAM WITH MOST TESTED QUESTIONS AND
ANSWERS | GRADED A+ | ASSURED SUCCESS WITH DETAILED
RATIONALES
28) What is always true about the sum of the interior angles of a triangle?
A. It equals 90°
B. It equals 270°
C. It depends on side length
D. It equals 180°
Rationale: Any triangle’s interior angles sum to a straight angle, which is 180°.
29) If the angles of a triangle are in a ratio a:b:ca:b:ca:b:c, which equation correctly finds xxx
to determine the angles ax,bx,cxax, bx, cxax,bx,cx?
A. ax+bx+cx=360ax+bx+cx=360ax+bx+cx=360
B. x(a+b+c)=90x(a+b+c)=90x(a+b+c)=90
C. ax+bx+cx=180ax+bx+cx=180ax+bx+cx=180 (equivalently
x(a+b+c)=180x(a+b+c)=180x(a+b+c)=180)
D. a+b+c=xa+b+c=xa+b+c=x
Rationale: Triangle interior angles sum to 180°, so x(a+b+c)=180x(a+b+c)=180x(a+b+c)=180.
30) Two whole numbers AAA and BBB have LCM 180 and GCF 12. Which value could be
A+BA+BA+B?
A. 72
B. 84
C. 96
D. 108
Rationale: A valid pair is A=36A=36A=36 and B=60B=60B=60.
gcd(36,60)=12\gcd(36,60)=12gcd(36,60)=12,
lcm(36,60)=180\mathrm{lcm}(36,60)=180lcm(36,60)=180, and 36+60=9636+60=9636+60=96.
, ESTUDYR
FRACTIONS AND MIXED NUMBERS
31) When subtracting mixed numbers with like denominators, if the minuend’s fractional
numerator is smaller than the subtrahend’s, what should you do?
A. Subtract anyway and keep the negative fraction
B. Multiply denominators
C. Regroup/borrow from the whole number OR convert to improper fractions, then subtract
D. Add the fractions first
Rationale: You must borrow 1 whole (convert to equivalent fraction) or use improper fractions
to subtract correctly.
RATES, PERCENT, AND WORD PROBLEMS
32) A vehicle travels for RRR hours at 65 mph. If it gets 24 mpg, what expression gives gallons
used?
A. 2465R\frac{24}{65R}65R24
B. 6524R\frac{65}{24R}24R65
C. 24(65R)24(65R)24(65R)
D. 65R24\frac{65R}{24}2465R
Rationale: Distance =65R=65R=65R miles. Gallons
=milesmpg=65R24=\frac{\text{miles}}{\text{mpg}}=\frac{65R}{24}=mpgmiles=2465R.
33) A TV price xxx is increased by 25% then discounted by 35% later. What is the final price
expression?
A. (1.25)(1.35)x(1.25)(1.35)x(1.25)(1.35)x
B. (0.75)(0.65)x(0.75)(0.65)x(0.75)(0.65)x
C. (1.35)(0.75)x(1.35)(0.75)x(1.35)(0.75)x
D. (1.25)(0.65)x(1.25)(0.65)x(1.25)(0.65)x
Rationale: Increase 25% ⇒ multiply by 1.25. Decrease 35% ⇒ multiply by 0.65.
34) A person earns $1200. They spend 14\frac{1}{4}41 on rent. From the remainder, they
spend 20% on utilities and 25% on food. How much money is left?
