Question
The average age of 20 girls is 54 years. If the age of
two more girls is added the average decreases by half a year. What is the sum of the age of new girls?Solution
Total age of 20 girls = 20 × 54 = 1080 years If the age of two more girls is added the average decreases by half a year, ∴ Total age of 22 girls = 53.5 × 22 = 1177 Now, sum of the age of new girls = 1177 – 1080 = 97 years
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