The average weight of some students in a class was 60 5 kg When 8 students whose average weight was ...........

Quantitative Aptitude (CPO) Average

The average weight of some students in a class was 60.5 kg. When 8 students, whose average weight was 65 kg, joined the class,

then the average weight ofall the students increased by 0.9 kg. The numberofstudentsin theclass,initially, was:

This questions was previously asked in

SSC CPO 9th Dec 2019 Shift-2

- Let's denote the initial number of students as \( n \).

- The initial total weight of the students is \( 60.5n \) kg.

- 8 new students join the class with an average weight of 65 kg, adding a total weight of \( 8 \times 65 = 520 \) kg.

- The new average weight becomes 61.4 kg as it increases by 0.9 kg (i.e., 60.5 + 0.9).

- The new equation for the total weight with \( n + 8 \) students is \( 61.4(n + 8) \).

- Set up the equation: \( 60.5n + 520 = 61.4(n + 8) \).

- Solve for \( n \) to get \( 60.5n + 520 = 61.4n + 491.2 \).

- Rearranging, \( 520 - 491.2 = 61.4n - 60.5n \).

- Solving, \( 28.8 = 0.9n \) gives \( n = 32 \).

Therefore, the correct answer is:

- Option 1: 32

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