maths之英文題的百分數 好難 help me

1. A hawker bought 750 eggs, 25of them were broken. Find the percentage of eggs that were broken.

The percentage of eggs broken was 25/750 x 100% =3.33%

2. 450 boys and 550 girls sat an examination, 80% of boys and 60% girls passed the examination. Find
a) the number of boys who failed the examination

450 x (1-0.8)=90 boys
explanation: There were 80% of boys passing the examination, which meaned 20% of them got passed.

(b) the number of girls who failed the examination;
550 x (1-0.6)=220girls

(c) the percentage of students who failed the examination.
The total number of students participating in the examination was 450+550=1000students, and there were 310 students (90boys and 220 girls) getting a fail in it. Therefore, the percentage of students who failed the examination was 310/1000 x 100%= 31%

Hope you can understand my explanations.

1.25/750*100%
3又3分1

2a.90
2b.220
2c.90+220/450+550 *100%
31%

1.

Percentage of eggs that were broken = 25 / 750 * 100% = 3.3333%


2.

(a)

80% of boys passed the examination imply that 20% of the boys failed the examination.

Number of boys who failed the examination
= 450 * 20%
= 90

(b)

60% of girls passed the examination imply that 40% of the girls failed the examination.

Number of girls who failed the examination
= 550 * 40%
= 220

(c)

Total number of students = 450 + 550 = 1000
Total number of students who failed the examination = 90 + 220 = 310
Percentage of students who failed the examination = 310 / 1000 * 100% = 31%

1.25/750x100%=33 1/3%
2.450x (1-80%)=90
b.550x(1-60%)=220
c.(90+220)/(450+550)x100%=31%