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Question
From the following table, determine if x and y are in direct proportion or not.
| x | 3 | 6 | 15 | 20 | 30 |
| y | 12 | 24 | 45 | 60 | 120 |
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Solution
In direct proportion, `x/y = k` ...(Constant)
For table
| x | 3 | 6 | 15 | 20 | 30 |
| y | 12 | 24 | 45 | 60 | 120 |
⇒ `x/y = 3/12, 6/24, 15/45, 20/60, 30/120`
i.e. `1/4, 1/4, 1/3, 1/3, 1/4`
So, is not in direct proportion.
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