1. **Find values of percentages:** (a) 5% of 120 cm = $\frac{5}{100} \times 120 = 6$ cm (b) 30% of 60 = $\frac{30}{100} \times 60 = 18$ (c) 45% of 2000 g = $\frac{45}{100} \times 2000 = 900$ g (d) 90% of 720 pupils = $\frac{90}{100} \times 720 = 648$ pupils (e) 50% of 180 litres = $\frac{50}{100} \times 180 = 90$ litres (f) 55% of 426 = $\frac{55}{100} \times 426= 234.3$ 2. **Money left after spending 9 1/2 (9.5) (assuming 9.5 means 9.5 units spent):** If spent is $9.5$ units of money (assuming total money $m$), percentage spent is $\frac{9.5}{m} \times 100$, but question likely means 9 1/2% spent (9.5%), so money left is $100\%-9.5\% = 90.5\%$. 3. **Percentage absent:** Total pupils = 30, present = 24, absent = 30 - 24 = 6 Percentage absent = $\frac{6}{30} \times 100 = 20\%$ 4. **Science students admitted:** 60% of 120 = $\frac{60}{100} \times 120 = 72$ students 5. **Interest on ₦420 at 9 1/2%:** Interest = $\frac{9.5}{100} \times 420 = 39.9$ 6. **Express as percentage:** (a) $\frac{78}{120} \times 100 = 65\%$ (b) $\frac{62}{80} \times 100 = 77.5\%$ 7. **Fractions as percentages:** (a) $\frac{1}{7} \approx 0.142857 \Rightarrow 14.29\%$ (b) $\frac{5}{6} \approx 0.8333 \Rightarrow 83.33\%$ (c) $\frac{3}{8} = 0.375 \Rightarrow 37.5\%$ (d) $\frac{3}{5} = 0.6 \Rightarrow 60\%$ 8. **Percentages as decimals:** (a) 12 1/2% = 12.5% = 0.13 (b) 65% = 0.65 (c) 33 1/3% = 33.33% = 0.33 (d) 47% = 0.47 9. **What percentage?** (a) $\frac{500}{1750} \times 100 = 28.57\%$ (b) 3 km = 3000 m, so $\frac{200}{3000} \times 100 = 6.67\%$ (c) 2 1/2 hr = 150 min, $\frac{45}{150} \times 100 = 30\%$ (d) 7 1/2 am (7.5 hr), 2 1/2 am (2.5 hr), difference = 5 hr Ratio $\frac{2.5}{7.5} \times 100 = 33.33\%$ 10. **Items wrong:** Total 60, correct 52, wrong = 8 Percentage wrong = $\frac{8}{60} \times 100 = 13.33\%$ 11. **Land vacant:** Building occupies $\frac{3}{8}$, vacant = $1-\frac{3}{8} = \frac{5}{8}$ Percentage vacant = $\frac{5}{8} \times 100 = 62.5\%$ **Extra problems:** - Playground grass covers $\frac{2}{5} \Rightarrow 40\%$, Cement covers $60\%$ - Percentage loss = $\frac{350-340}{350} \times 100 = 2.86\%$ - Votes difference percentage = $\frac{55-25}{25} \times 100 = 120\%$ - Passengers: Adults = 50% of 40 = 20, Men = 60% of adults = 12, Women = 20 - 12 = 8, Children = 40 - 20 = 20 - Salary increase by 13 1/3% = $\frac{40}{3}\%$, New salary = $4800 \times (1 + \frac{40}{300}) = 4800 \times 1.1333 = 5440$ - Rally men = 40% of 800 = 320, Women = 80% of men = 256, Children = 800 - (320 + 256) = 224 - Children as percentage of women = $\frac{224}{256} \times 100 = 87.5\%$ - Shooting scores: Musa: $\frac{72}{90} \times 100 = 80\%$ Adabara: $\frac{102}{120} \times 100 = 85\%$ Adabara better - Yetunde's best subject %: Geography: $\frac{48}{80} \times 100 = 60\%$ English: $\frac{78}{120} \times 100 = 65\%$ Mathematics: $\frac{102}{150} \times 100 = 68\%$ General Science: $\frac{100}{125} \times 100 = 80\%$ Social Studies: $\frac{63}{90} \times 100 = 70\%$ Home Economics: $\frac{45}{60} \times 100 = 75\%$ Best subject: General Science - Total mark for 61% score: Given 399 is 57%, so total mark $= \frac{399}{0.57} \approx 700$ For 61%, mark = $0.61 \times 700 = 427$ - Candidate overall %: Total marks = 20 + 40 = 60 Marks obtained = 15 + 30 = 45 Overall % = $\frac{45}{60} \times 100 = 75\%$ - Money left after spending 1/4: Spent 25%, left 75% - Maximum mark for Sanusi: 656 = 82%, so max mark = $\frac{656}{0.82} = 800$