
Please help to solve. Thanks.
Please help to solve. Thanks.
We will set up an equation like this:
2/5X+ 1/2Y= 249
X+Y= 567
x: is the number of female students
Y: is the number of male students
B is the correct answer?
redactle unlimited
Use Elimination Method
Let G represent the girls in the hall.
Let B represent the boys in the hall.
Wear glasses ➜ (2/5)G + (1/2)B = 249 students — Equation (1)
Don’t wear glasses ➜ (3/5)G + (1/2)B = 567 – 249 = 318 students — Equation (2)
Since the fraction of boys who wear glasses and don’t wear glasses are both one half (1/2), subtracting Equation (1) from Equation (2) would eliminate the boys totally (zero), and give a remainder of (1/5)G.
(1/5)G ➜ 318 – 249 = 69 girls
Total girls in hall ➜ 69 x 5 = 345 girls
Total boys in hall ➜ 567 – 345 = 222 boys
Fraction of boys in hall ➜ 222/567 = 74/189 (simplest form) — Part (a) answer
Girls who wear glasses (at first) ➜ 69 x 2 = 138 girls
Girls who wear glasses (new) ➜ 138 – 5 = 133 girls
Total girls in hall (new) ➜ 345 – 5 = 340 girls
Fraction of remaining girls who wear glasses ➜ 133/340 — Part (b) answer
*To learn more problem-solving methods, visit us at Miss J Classroom – Maths is Fun
Use Elimination Method
Let G represent the girls in the hall.
Let B represent the boys in the hall.
Wear glasses ➜ (2/5)G + (1/2)B = 249 students — Equation (1)
Don’t wear glasses ➜ (3/5)G + (1/2)B = 567 – 249 = 318 students — Equation (2)
Since the fraction of boys who wear glasses and don’t wear glasses are both one half (1/2), subtracting Equation (1) from Equation (2) would eliminate the boys totally (zero), and give a remainder of (1/5)G.
(1/5)G ➜ 318 – 249 = 69 girls
Total girls in hall ➜ 69 x 5 = 345 girls
Total boys in hall ➜ 567 – 345 = 222 boys
Fraction of boys in hall ➜ 222/567 = 74/189 (simplest form) — Part (a) answer
Girls who wear glasses (at first) ➜ 69 x 2 = 138 girls
Girls who wear glasses (new) ➜ 138 – 5 = 133 girls
Total girls in hall (new) ➜ 345 – 5 = 340 girls
Fraction of remaining girls who wear glasses ➜ 133/340 — Part (b) answer
*To learn more problem-solving methods, visit us at Miss J Classroom – Maths is Fun