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What number should be added to each of the numbers 55, 100, 65 and 116, so that the resulting numbers are in continued proportion?
- A20
- B10
- C5
- D15
Answer not set
Discussion 1
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CCommunity
Let number be x
Then, according to the question,
(55 + x) : (100 + x) = (65 + x) : (116 + x)
⇒ (55 + x) × (116 + x) = (65 + x) × (100 + x)
⇒ 6380 + 171x + x2 = 6500 + 165x + x2
⇒ 6x = 120
⇒ x = 20
∴ 20 should be added to the numbers so that they are in continued proportion.
Then, according to the question,
(55 + x) : (100 + x) = (65 + x) : (116 + x)
⇒ (55 + x) × (116 + x) = (65 + x) × (100 + x)
⇒ 6380 + 171x + x2 = 6500 + 165x + x2
⇒ 6x = 120
⇒ x = 20
∴ 20 should be added to the numbers so that they are in continued proportion.