InterviewSolution
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The average height of 8 students in a class is 80 cm. If the height of 4 more students is included, then average height increased to 82 cm. Find the sum of the height of the new students.1. 240 cm2. 120 cm3. 344 cm4. 560 cm |
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Answer» Correct Answer - Option 3 : 344 cm Given∶ Average height of 8 students = 80 cm Average height of 12 students = 82 cm Formula used∶ Average = Sum of all observation / Number of observation Calculation∶ Sum of height of 8 students = 640 cm Sum of height of 12 students = 984 cm Sum of height of 4 students = 984 - 640 ⇒ 344 cm ∴ The sum of the height of the new students is 344 cm. Alternate method∶ If one or more quantities are added in a group, then the sum of new quantities added is calculated by given formula∶ Sum of new quantity = [Change in number of quantities × Original average] + [Change in average × Final number of quantities] = [4 × 80 + 2 × 12] ⇒ 344 ∴ The sum of the height of the new students is 344 cm. |
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