F3 Quiz2 Ans

F.3 Mathematics – Quiz 2 (Answer)

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Kwok Tak Seng Catholic Secondary School F.3 Mathematics Quiz 2 – Significant Figures and Scientific Notation (Answer) 1. 3. 5. 7. 9. 11. 13.

328 569 = 328 600 729.384 = 730 0.803 3 = 0.803

(cor. to 4 sig. fig.) 2. (cor. to 2 sig. fig.) 4. (cor. to 3 sig. fig.) 6. 6 8. 8 634 000 = 8.634 × 10 −5 10. 0.000 013 45 = 1.345 × 10 5 12. 2.43 × 10 = 243 000 5 3 14. (3 × 10 ) × (6.28 × 10 )

3 446.193 7 = 3 446

(cor. to the nearest integer)

(b) (c)

3 446.193 7 = 3 446.194 (cor. to 3 d.p.) 3 446.193 7 = 3 446.2 (cor. to 5 sig. fig.)

18. (a)

Exterior angle of a regular 11-sided polygon =

(b)

360° 11

(ext. ∠ of a regular polgon)

= 32.727 2…° = 32.7° (cor. to 3 sig. fig.) Interior angle of a regular 11-sided polygon = 180° − 32.727 2…° (adj. ∠s on st. line) = 147.272 7…° = 147° (cor. to 3 sig. fig.)

19. (a)

p = 57 000 000 = 5.7 × 107 q = 2 000 000

(b)

(c)

(cor. to 3 sig. fig.) (cor. to 3 sig. fig.) (cor. to 4 sig. fig.)

706 010 000 = 7.060 1 × 108 0.000 140 = 1.40 × 10−4 7.601 × 10−3 = 0.007 601 (4.2 × 10−3) ÷ (2.1 × 10−5) = (4.2 ÷ 2.1) × (10−3 ÷ 10−5) = 2 × 10-3-(-5) = 2 × 102 16. 8 × 10−4 + 5.2 × 10−5 = 10−5 × (8 × 10 + 5.2) = 85.2 × 10−5 = 8.52 × 10−4

= (3 × 6.28) × (105 × 103) = 18.84 × 108 = 1.884 × 109 15. 6.4 × 1010 − 2.73 × 108 = 108 × (6.4× 102 − 2.73) = 637.27 × 108 = 6.3727 × 1010 17. (a)

25 702 = 25 700 8.403 = 8.40 0.010 304 = 0.010 30

= 2 × 106 pq = (5.7 × 107) × (2 × 106) = (5.7 × 2) × 107+6 = 11.4 × 1013 = 1.14 × 1014 p + q = 5.7 × 107+ 2 × 106 = 106 × (5.7 × 10 + 2) = 59 × 106 = 5.9 × 107