1. **Problem:** Simplify the ratio 36:90 to its lowest terms.
**Formula:** To simplify a ratio, divide both terms by their greatest common divisor (GCD).
**Work:** GCD of 36 and 90 is 18.
$$\frac{36}{\cancel{18}} : \frac{90}{\cancel{18}} = 2 : 5$$
**Answer:** The ratio in lowest terms is 2:5.
2. **Problem:** Find the sale price after a 30% discount on a $50 hoodie.
**Formula:** Sale price = Regular price - (Discount rate × Regular price)
**Work:**
$$30\% = 0.30$$
$$\text{Discount} = 0.30 \times 50 = 15$$
$$\text{Sale price} = 50 - 15 = 35$$
**Answer:** The sale price is 35.
3. **Problem:** Simplify $\frac{5}{8} \div \frac{2}{3}$ to lowest terms.
**Formula:** Division of fractions: $\frac{a}{b} \div \frac{c}{d} = \frac{a}{b} \times \frac{d}{c}$
**Work:**
$$\frac{5}{8} \times \frac{3}{2} = \frac{5 \times 3}{8 \times 2} = \frac{15}{16}$$
**Answer:** $\frac{15}{16}$
4. **Problem:** Simplify $6 \frac{1}{4} \times \frac{3}{8}$ to lowest terms.
**Formula:** Convert mixed number to improper fraction, then multiply.
**Work:**
$$6 \frac{1}{4} = \frac{25}{4}$$
$$\frac{25}{4} \times \frac{3}{8} = \frac{75}{32}$$
**Answer:** $\frac{75}{32}$ or $2 \frac{11}{32}$
5. **Problem:** Lydia spends $24 on entertainment, which is $\frac{2}{5}$ of her clothes expenses. Find clothes expenses.
**Formula:** Entertainment = $\frac{2}{5}$ × Clothes
**Work:**
$$24 = \frac{2}{5} \times \text{Clothes}$$
$$\text{Clothes} = \frac{24}{\frac{2}{5}} = 24 \times \frac{5}{2} = 60$$
**Answer:** Lydia spends 60 on clothes.
6. **Problem:** Find volume of right triangular prism with base area 50 cm² and height 8 cm.
**Formula:** Volume = Base area × Height
**Work:**
$$V = 50 \times 8 = 400$$
**Answer:** Volume is 400 cm³.
7. **Problem:** Solve $3(x - 4) = 15$ for $x$.
**Formula:** Distribute and isolate $x$.
**Work:**
$$3x - 12 = 15$$
$$3x = 15 + 12 = 27$$
$$x = \frac{27}{3} = 9$$
**Answer:** $x = 9$
8. **Problem:** Delivery cost $c = 4m + 5$, find cost for $m=9$ pieces.
**Work:**
$$c = 4 \times 9 + 5 = 36 + 5 = 41$$
**Answer:** Cost is 41.
9. **Problem:** Find two whole numbers between which $\sqrt{51}$ lies.
**Work:**
$$7^2 = 49 < 51 < 64 = 8^2$$
**Answer:** Between 7 and 8.
10. **Problem:** Find area of square with side 8 cm.
**Formula:** Area = side²
**Work:**
$$8^2 = 64$$
**Answer:** 64 cm².
11. **Problem:** If 240 grams cost 4, how many grams for 3?
**Formula:** Use ratio.
**Work:**
$$\frac{240}{4} = \frac{x}{3}$$
$$x = \frac{240}{4} \times 3 = 180$$
**Answer:** 180 grams.
12. **Problem:** Use Pythagorean theorem to find unknown square area.
**Formula:** $a^2 + b^2 = c^2$
**Work:**
Known squares: 49 and 81
$$49 + 81 = 130$$
**Answer:** Unknown square area is 130.
13. **Problem:** Calculate $6 \times 4 - (-7)$.
**Work:**
$$24 + 7 = 31$$
**Answer:** 31.
14. **Problem:** Volume of block 80 cm × 20 cm × 30 cm.
**Formula:** Volume = length × width × height
**Work:**
$$80 \times 20 \times 30 = 48000$$
**Answer:** 48000 cm³.
15. **Problem:** Find $\frac{3}{5}$ of 30.
**Work:**
$$\frac{3}{5} \times 30 = 18$$
**Answer:** 18.
16. **Problem:** Temperature drops 4°C every 2 hours, find change after 8 hours.
**Work:**
$$\frac{4}{2} = 2 \text{°C per hour}$$
$$2 \times 8 = 16$$
**Answer:** Temperature drops 16°C.
17. **Problem:** 1/4 of cards are rare; 10 rare cards total. Find total cards.
**Work:**
$$\frac{1}{4} \times \text{Total} = 10$$
$$\text{Total} = 10 \times 4 = 40$$
**Answer:** 40 cards.
18. **Problem:** Express $\frac{6}{15}$ as decimal.
**Work:**
$$\frac{6}{15} = 0.4$$
**Answer:** 0.4
19. **Problem:** Distance $d=rt$, find time $t$ for 1200 km at 800 km/h.
**Formula:** $t = \frac{d}{r}$
**Work:**
$$t = \frac{1200}{800} = 1.5$$
**Answer:** 1.5 hours.
20. **Problem:** Solve $\frac{2}{3} = \frac{x}{60}$ for $x$.
**Work:**
$$x = \frac{2}{3} \times 60 = 40$$
**Answer:** $x=40$
21. **Problem:** Find 150% of 80.
**Work:**
$$150\% = 1.5$$
$$1.5 \times 80 = 120$$
**Answer:** 120
22. **Problem:** Simplify $\frac{2}{3} \times \frac{3}{4} \div \frac{1}{2}$.
**Work:**
$$\frac{2}{3} \times \frac{3}{4} = \frac{6}{12} = \frac{1}{2}$$
$$\frac{1}{2} \div \frac{1}{2} = 1$$
**Answer:** 1
23. **Problem:** Evaluate $(-22) - (-12)$.
**Work:**
$$-22 + 12 = -10$$
**Answer:** -10
24. **Problem:** Evaluate $(-10) \times (-6) \times (-8)$.
**Work:**
$$(-10) \times (-6) = 60$$
$$60 \times (-8) = -480$$
**Answer:** -480
25. **Problem:** Evaluate $(-28) \div (-7) \times (-2)$.
**Work:**
$$-28 \div -7 = 4$$
$$4 \times -2 = -8$$
**Answer:** -8
26. **Problem:** Approximate $\sqrt{27}$ to nearest whole number.
**Work:**
$$5^2=25 < 27 < 36=6^2$$
Closer to 5.
**Answer:** 5
27. **Problem:** Evaluate $14^2$.
**Work:**
$$14 \times 14 = 196$$
**Answer:** 196
28. **Problem:** Solve $2x + 4 = -8$.
**Work:**
$$2x = -8 - 4 = -12$$
$$x = \frac{-12}{2} = -6$$
**Answer:** $x = -6$
29. **Problem:** Solve $67 = 4x + 3$.
**Work:**
$$4x = 67 - 3 = 64$$
$$x = \frac{64}{4} = 16$$
**Answer:** $x=16$
30. **Problem:** Solve $\frac{x}{5} - 4 = -2$.
**Work:**
$$\frac{x}{5} = -2 + 4 = 2$$
$$x = 2 \times 5 = 10$$
**Answer:** $x=10$
31. **Problem:** Find 125% of 60.
**Work:**
$$125\% = 1.25$$
$$1.25 \times 60 = 75$$
**Answer:** 75
32. **Problem:** Simplify $\frac{1}{4} + \frac{3}{8}$.
**Work:**
$$\frac{1}{4} = \frac{2}{8}$$
$$\frac{2}{8} + \frac{3}{8} = \frac{5}{8}$$
**Answer:** $\frac{5}{8}$
33. **Problem:** Simplify $\frac{2}{5} \times \frac{3}{4}$.
**Work:**
$$\frac{6}{20} = \frac{3}{10}$$
**Answer:** $\frac{3}{10}$
34. **Problem:** Simplify $\frac{5}{8} \div \frac{2}{5}$.
**Work:**
$$\frac{5}{8} \times \frac{5}{2} = \frac{25}{16}$$
**Answer:** $\frac{25}{16}$
35. **Problem:** Simplify $\frac{3}{4} \div \frac{5}{9}$.
**Work:**
$$\frac{3}{4} \times \frac{9}{5} = \frac{27}{20}$$
**Answer:** $\frac{27}{20}$
36. **Problem:** Simplify $\frac{11}{12} - \frac{1}{2} \times \left(\frac{1}{4} + \frac{2}{3}\right)$.
**Work:**
$$\frac{1}{4} + \frac{2}{3} = \frac{3}{12} + \frac{8}{12} = \frac{11}{12}$$
$$\frac{1}{2} \times \frac{11}{12} = \frac{11}{24}$$
$$\frac{11}{12} - \frac{11}{24} = \frac{22}{24} - \frac{11}{24} = \frac{11}{24}$$
**Answer:** $\frac{11}{24}$
37. **Problem:** Evaluate $(-5) + 7$.
**Work:**
$$2$$
**Answer:** 2
38. **Problem:** Evaluate $7 \times (-5)$.
**Work:**
$$-35$$
**Answer:** -35
39. **Problem:** Evaluate $(-8) \times (-9)$.
**Work:**
$$72$$
**Answer:** 72
40. **Problem:** Evaluate $32 \div (-4)$.
**Work:**
$$-8$$
**Answer:** -8
41. **Problem:** Evaluate $(-4) \times 3 \times (-5)$.
**Work:**
$$(-4) \times 3 = -12$$
$$-12 \times (-5) = 60$$
**Answer:** 60
42. **Problem:** Evaluate $16 \div (-8) \times 6$.
**Work:**
$$16 \div (-8) = -2$$
$$-2 \times 6 = -12$$
**Answer:** -12
43. **Problem:** Order from smallest to greatest: $\frac{5}{6} \times 6$, 12.5% of 24, $\frac{2}{3} \times 9$, 20% of 20.
**Work:**
$$\frac{5}{6} \times 6 = 5$$
$$12.5\% \times 24 = 3$$
$$\frac{2}{3} \times 9 = 6$$
$$20\% \times 20 = 4$$
Order: 3, 4, 5, 6
**Answer:** 12.5% of 24, 20% of 20, $\frac{5}{6} \times 6$, $\frac{2}{3} \times 9$
44. **Problem:** Approximate $\sqrt{66}$ to nearest whole number.
**Work:**
$$8^2=64 < 66 < 81=9^2$$
Closer to 8.
**Answer:** 8
45. **Problem:** Evaluate $17^2$.
**Work:**
$$17 \times 17 = 289$$
**Answer:** 289
46. **Problem:** Solve $12 = -4x - 12$.
**Work:**
$$-4x = 12 + 12 = 24$$
$$x = \frac{24}{-4} = -6$$
**Answer:** $x = -6$
47. **Problem:** Solve $5(x + 2) = 40$.
**Work:**
$$x + 2 = \frac{40}{5} = 8$$
$$x = 8 - 2 = 6$$
**Answer:** $x=6$
48. **Problem:** Solve $-2(7x - 1) = -40$.
**Work:**
$$-14x + 2 = -40$$
$$-14x = -42$$
$$x = 3$$
**Answer:** $x=3$
49. **Problem:** Solve $-80 = -4(3x + 2)$.
**Work:**
$$-80 = -12x - 8$$
$$-12x = -72$$
$$x = 6$$
**Answer:** $x=6$
50. **Problem:** Solve $\frac{x}{4} + 9 = 20$.
**Work:**
$$\frac{x}{4} = 11$$
$$x = 44$$
**Answer:** $x=44$
Exam Review 8155Ed
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