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Girls form 60 per cent of a class and there are 18 girls. How many students are in the class?
A28
B30
C32
D36
Answer & Solution
Correct answer: B. 30
1. Let the total number of students be x.
2. 60 per cent of x = 18, so (60/100) x = 18.
3. x = (18 x 100) / 60 = 30.
4. Check: 60 per cent of 30 = 18 girls, leaving 12 boys.
_Source: NCERT Class 8 Maths Ch7 'Comparing Quantities', Example 1_
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