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  • 2) Mr Lim gave 3600 to his wife and two children altogether. His wife received 500 more than his son. His son received twice as much as his daughter. How much did Mr Lim’s wife received? (W.Bk 5A : pg 28 #6)

2) Mr Lim gave 3600 to his wife and two children altogether. His wife received 500 more than his son. His son received twice as much as his daughter. How much did Mr Lim’s wife received? (W.Bk 5A : pg 28 #6)

2) Mr Lim gave 3600 to his wife and two children altogether. His wife received 500 more than his son. His son received twice as much as his daughter. How much did Mr Lim's wife received? (W.Bk 5A : pg 28 #6)

Answer

Answer: Mr. Lim’s wife received $1,700.

Explanation: To solve this problem, we use algebraic equations to represent the relationships and total amount given. We define variables for the amounts received by the son and daughter, and express the wife’s amount in terms of these variables.

Steps:

  1. Define Variables:
  • Let \( x \) be the amount the daughter received.
  • Then the son received \( 2x \) (since he received twice as much as the daughter).
  • The wife received \( 2x + 500 \) (since she received $500 more than the son).
  1. Set Up the Equation:
  • The total amount given is $3,600. Therefore, the equation is:

\[ x + 2x + (2x + 500) = 3600 \]

  1. Simplify the Equation:
  • Combine like terms:

\[ 5x + 500 = 3600 \]

  1. Solve for \( x \):
  • Subtract 500 from both sides:

\[ 5x = 3100 \]

  • Divide by 5:

\[ x = 620 \]

  1. Calculate the Wife’s Amount:
  • Substitute \( x = 620 \) back into the expression for the wife’s amount:

\[ 2x + 500 = 2(620) + 500 = 1240 + 500 = 1740 \]

Therefore, Mr. Lim’s wife received $1,740.

Related

(2) O3 + H → O2 + OH k2 = 1.78×10^-11 cm^3 s^-1 (3) O + OH → O2 + H k3 = 4.40×10^-11 cm^3 s^-1 (5) O + HO2 → O2 + OH k5 = 3.50×10^-11 cm^3 s^-1 (6) H + HO2 → O2 + H2 k6 = 5.40×10^-12 cm^3 s^-1 (9) OH + HO2 → O2 + H2O2 k9 = 4.00×10^-11 cm^3 s^-1 (10) HO2 + HO2 → O2 + H2O2 k10 = 2.50×10^-12 cm s^-1 (11) O + O2 + M → O3 + M k11 = 1.05×10^-34 cm^6 s^-1 (14) H + O2 + M → HO2 + M k14 = 8.08×10^-32 cm^6 s^-1 (15) H + H + M → H2O + M k15 = 3.31×10^-27 cm^6 s^-1 (16) O2 + hv → 2 O k16 = (1.26×10^-8 s^-1) φ (17) H2O + hv → H + OH k17 = (3.4×10^-6 s^-1) φ (18) O3 + hv → O2 + O k18 = (7.10×10^-5 s^-1) φ

Table 1 Reactions, rate constants and activation energies used in the model* No. Reaction kopt (M⁻¹ s⁻¹) 1 OH + H₂ → H + H₂O 3.74 x 10⁷ 2 OH + HO₂ → HO₂ + OH⁻ 5 x 10⁹ 3 OH + H₂O₂ → HO₂ + H₂O 3.8 x 10⁷ 4 OH + O₂ → O₂ + OH 9.96 x 10⁹ 5 OH + HO₂ → O₂ + H₂O 7.1 x 10⁹ 6 OH + OH → H₂O₂ 5.3 x 10⁹ 7 OH + e⁻aq → OH⁻ 3 x 10¹⁰ 8 H + O₂ → HO₂ 2.0 x 10¹⁰ 9 H + HO₂ → H₂O₂ 2.0 x 10¹⁰ 10 H + H₂O₂ → OH + H₂O 3.44 x 10⁷ 11 H + OH → H₂O 1.4 x 10¹⁰ 12 H + H → H₂ 1.94 x 10¹⁰ 13 e⁻aq + O₂ → O₂⁻ 1.9 x 10¹⁰ 14 e⁻aq + O₂ → HO₂⁻ + OH⁻ 1.3 x 10¹⁰ 15 e⁻aq + HO₂ 2.0 x 10¹⁰ 16 e⁻aq + H₂O₂ 1.1 x 10¹⁰ 17 e⁻aq + HO₂ → OH + OH⁻ 1.3 x 10¹⁰ 18 e⁻aq + H⁺ → H 2.3 x 10¹⁰ 19 e⁻aq + e⁻aq → H₂ + OH⁻ + OH⁻ 2.5 x 10⁹ 20 HO₂ + O₂ → O₂ + HO₂ 1.3 x 10⁹ 21 HO₂ + HO₂ → O₂ + H₂O₂ 8.3 x 10⁵ 22 HO₂ + HO₂ → O₂ + OH + H₂O 3.7 23 HO₂ + HO₂ → O₂ + O₂ + OH + H₂O 7 x 10⁵ s⁻¹ 24 H⁺ + O₂⁻ → HO₂ 4.5 x 10¹⁰ 25 H⁺ + O₂⁻ → O₂ 2.0 x 10¹⁰ 26 H⁺ + OH⁻ 1.4 x 10¹¹ 27 H⁺ + HO₂⁻ 2 x 10¹⁰ 28 H₂O₂ → HO₂ + H⁺ + OH⁻ 2.5 x 10⁻⁵ s⁻¹ 29 H₂O₂ → H⁺ + OH⁻ 1.4 x 10⁻⁷ s⁻¹ 30 O₂ + O₂ → O₂ + HO₂ + OH⁻ 0.3 31 O₂ + H₂O₂ → O₂ + OH + OH 16 32

(2) O3 + H → O2 + OH k2 = 1.78×10^-11 cm^3 s^-1 (3) O + OH → O2 + H k3 = 4.40×10^-11 cm^3 s^-1 (5) O + HO2 → O2 + OH k5 = 3.50×10^-11 cm^3 s^-1 (6) H2O + O → 2 OH k6 = 5.40×10^-12 cm^3 s^-1 (9) OH + HO2 → O2 + H2O k9 = 4.00×10^-11 cm^3 s^-1 (10) HO2 + HO2 → O2 + H2O2 k10 = 2.50×10^-12 cm s^-1 (11) O + O2 + M → O3 + M k11 = 1.05×10^-34 cm^6 s^-1 (14) H + O2 + M → HO2 + M k14 = 8.08×10^-32 cm^6 s^-1 (15) OH + H + M → H2O + M k15 = 3.31×10^-27 cm^6 s^-1 (16) O2 + hv → 2 O k16 = (1.26×10^-8 s^-1) φ (17) H2O + hv → H + OH k17 = (3.4×10^-6 s^-1) φ (18) O3 + hv → O2 + O k18 = (7.10×10^-8 s^-1) φ

Table 1 Reactions, rate constants and activation energies used in the model* No. Reaction kopt (M−1 s−1) 1 OH + H2 → H + H2O 3.74 x 107 2 OH + HO2 → HO2 + OH− 5 x 109 3 OH + H2O2 → HO2 + H2O 3.8 x 107 4 OH + O2 → O2− + OH 9.96 x 109 5 OH + HO2 → O2 + H2O 7.1 x 109 6 OH + OH → H2O2 5.3 x 109 7 OH + eaq− → OH− 3 x 1010 8 OH + O2− → HO2 2.0 x 1010 9 H + O2 → HO2 2.0 x 1010 10 H + HO2 → H2O2 2.0 x 1010 11 H + H2O2 → OH + H2O 3.4 x 107 12 H + OH → H2O 1.4 x 1010 13 H + H → H2 7.9 x 109 14 eaq− + O2 → O2− 1.94 x 1010 15 eaq− + O2− → HO2− + OH− 1.3 x 1010 16 eaq− + HO2 → OH− + OH 2.5 x 1010 17 eaq− + H2O2 → OH + OH− 1.3 x 1010 18 eaq− + H → H− 2.5 x 1010 19 eaq− + eaq− + H2 + OH− 3.5 x 109 20 eaq− + H2O2 + OH− 4.5 x 109 21 HO2 + O2 → O2 + HO2 3.7 22 HO2 + HO2 → O2 + H2O2 3.7 23 HO2 + HO2 → O2 + OH + H2O 7 x 105 s−1 24 HO2− + O2 4.5 x 1010 25 H2O2 → 2OH 0.035 s−1 26 H+ + O2− → HO2 2 x 1010 27 H+ + HO2− → HO2 2 x 1010 28 H2O2 → H+ + HO2− 2.5 x 10−5 s−1 29 H2O2 → H+ + HO2− 2.5 x 10−5 s−1 30 O2− + O2 → HO2 + OH− 0.3 31 O2− + H2O2 → O2 + OH− + OH 16 32 1.8 x 107

(2) O3 + H → O2 + OH k2 = 1.78×10^-11 cm^3 s^-1 (3) O + OH → O2 + H k3 = 4.40×10^-11 cm^3 s^-1 (5) O + HO2 → O2 + OH k5 = 3.50×10^-11 cm^3 s^-1 (6) H2O → O + H2 k6 = 5.40×10^-12 cm^3 s^-1 (9) OH + HO2 → O2 + H2O k9 = 4.00×10^-11 cm^3 s^-1 (10) HO2 + HO2 → O2 + H2O2 k10 = 2.50×10^-12 cm s^-1 (11) O + O2 + M → O3 + M k11 = 1.05×10^-34 cm^6 s^-1 (14) H + O2 + M → HO2 + M k14 = 8.08×10^-32 cm^6 s^-1 (15) OH + H + M → H2O + M k15 = 3.31×10^-27 cm^6 s^-1 (16) O2 + hv → 2 O k16 = (1.26×10^-8 s^-1) φ (17) H2O + hv → H + OH k17 = (3.4×10^-6 s^-1) φ (18) O3 + hv → O2 + O k18 = (7.10×10^-8 s^-1) φ