Answer:
quantity a is halfed
Corrected question;
A quantity a varies inversely as a quantity b, if, when b changes a changes in the inverse ratio. What happens to the quantity a if the quantity b doubles?
Explanation:
Analysing the question;
A quantity a varies inversely as a quantity b,
a ∝ 1/b
a = k/b ......1
when b changes a changes in the inverse ratio;
Since the change at the same ratio but inversely, k = 1
So, equation 1 becomes;
a = 1/b
If the quantity b doubles,
ab = 1
a1b1 = a2b2
When b doubles, b2 = 2b1
a1b1 = a2(2b1)
Making a2 the subject of formula;
a2 = a1b1/(2b1)
a2 = a1/2
Therefore, when b doubles, a will be divided by 2, that means a is halfed.