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Question
a and b are inversely proportional to each other and are positive. If a increases by 100%, then b decreases by
Options
50%
75%
10%
200%
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Solution
50%
Explanation:
a and b are inversely proportional
So, `" a" alpha1/"b"⇒ "a"="k"/"b".`
⇒ ab = k , ..........(where k = constant)
`⇒"b"="k"/"a"`
when a is increases by 100%
`∴ "a"+"a"xx100/100=2"a".`
then, 2 a . b' = k.
`"b"' = "k"/2"a"`
% decrease in b = `(("b"-"b"')/"b")xx100`
`=(("k"/"a"-"k"/(2"a")))/("k"/"a")xx100`
= 50%
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