Question 8 - Figure it out - Page 28, 29, 30 - Chapter 1 Class 8 - Fractions in Disguise (Ganita Prakash II)

Transcript

Question 8 A school is organising an excursion for its students. 40% of them are Grade 8 students and the rest are Grade 9 students. Among these Grade 8 students, 60% are girls. [Hint: Drawing a rough diagram can help]. (i) What percentage of the students going to the excursion are Grade 8 girls? (ii) If the total number of students going to the excursion is 160, how many of them are Grade 8 girls?Given Total number of students = 160 First, we find number of Grade 8 girls, and then we find their percentage Now, Number of Grade 8 student = 40% of Total students = 40% × Total students = 40/100 × 160 = 4 × 16 = 64 Given that amongst Grade 8 students, 60% are girls Thus, Number of Grade 8 girls = 60% of Number of Grade 8 students = 60% × Number of Grade 8 students = 60/100 × 64 = 6/10 × 64 = 384/10 = 38.4 Thus, Number of Grade 8 girls are 38.4 Note: Since we cannot have 0.4 of a student, there is likely a typo in the question's numbers (perhaps the total was meant to be 150). However, based strictly on the math provided: 38.4. Now, we have to find Percentage of the students going to the excursion are Grade 8 girls Thus, Percentage of Grade 8 girls = (𝑵𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝑮𝒓𝒂𝒅𝒆 𝟖 𝒈𝒊𝒓𝒍𝒔)/(𝑻𝒐𝒕𝒂𝒍 𝒔𝒕𝒖𝒅𝒆𝒏𝒕𝒔 𝒈𝒐𝒊𝒏𝒈 𝒕𝒐 𝒆𝒙𝒄𝒖𝒓𝒔𝒊𝒐𝒏) × 100 = 38.4/160 × 100 = 38.4 × 100/160 = 384/10 × 100/160 = 38400/1600 = 𝟑𝟖𝟒/𝟏𝟔 = 96/4 = 24 % Thus, 24% of the total students are Grade 8 girls