Example 1 - Chapter 2 Class 7 Fractions and Decimals

Transcript

Example 1 (i) In a class of 40 students 1/5 of the total number of students like to study English, 2/5 of the total number like to study Mathematics and the remaining students like to study Science. (i) How many students like to study English? Total students = 40 Given that, 1/5 students like to study English ∴ Students who liked to study English = 𝟏/𝟓 × Total students = 1/5 × 40 = 8 Example 1 (ii) In a class of 40 students 1/5 of the total number of students like to study English, 2/5 of the total number like to study Mathematics and the remaining students like to study Science. (ii) How many students like to study Mathematics? Given that, 2/5 students like to study Mathematics ∴ Students who liked to study Mathematics = 𝟐/𝟓 × Total students = 2/5 × 40 = 2 × 8 = 16 Example 1 (iii) In a class of 40 students 1/5 of the total number of students like to study English, 2/5 of the total number like to study Mathematics and the remaining students like to study Science. (iii) What fraction of the total number of students like to study ScienceNow, Total students = Students who liked English + Students who liked Mathematics + Students who liked Science 40 = 8 + 16 + Students who liked Science 40 = 24 + Students who liked Science 40 − 24 = Students who liked Science 16 = Students who liked Science Students who liked Science = 16 Therefore, Fraction of students who liked Science = (𝑆𝑡𝑢𝑑𝑒𝑛𝑡𝑠 𝑤ℎ𝑜 𝑙𝑖𝑘𝑒 𝑆𝑐𝑖𝑒𝑛𝑐𝑒)/(𝑇𝑜𝑡𝑎𝑙 𝑠𝑡𝑢𝑑𝑒𝑛𝑡𝑠) = 𝟏𝟔/𝟒𝟎 = 16/40 = 8/20 = 4/10 = 𝟐/𝟓