Find Tuition/Enrichment Centres

AskQ logo

STUCK ON HOMEWORK?

ASK FOR HELP FROM OUR KIASUPARENTS.COM COMMUNITY!

Question

Answer

The average marks for the boys and girls was 82.

The average for the boys was 79.

82 – 79 = 3

There are 20 boys.

20 × 3 = 60

The average for the girls was 86.

86 – 82 = 4

60 ÷ 4 = 15

There are 15 girls. 20 boys and 15 girls = 35 children.

The average after Nicole took the test was 82.5.

82.5 – 82 = 0.5

35 × 0.5 = 17.5

Nicole’s score = 82.5 + 17.5 = 100 [Answer for part (a)]

Average scored by the girls = (15 × 86 + 100) ÷ 16 = 

86.875 = 86.9 (correct to 1 decimal place) [Answer for part (b)]

2 Replies 0 Likes

82 – 79 = 3 here what is 3? 

89 is total class average and 79 is only boys average then 3 regards?

1 Reply 0 Likes

The boys’ average of 79 is lower than the class average of 82. There are 20 boys so 20 x 3 = 60 marks must be made up by the girls, whose average score is above the class average of 82. The girls’ average is 86. 86 – 82 = 4. 60/4 = 15 girls.

15 girls x 4 marks above the average = 60 marks, which makes up for the boys’ 60 marks below the average  

1 Reply 0 Likes

thank you for clear explanation…

0 Replies 0 Likes

thank you

 

0 Replies 0 Likes
Find Tuition/Enrichment Centres