Oh come off it Yak. And how did you come away with a copy of the paper? And if you did, what's this about ounces, and "way" instead of "weigh"?
Think everyone should steer clear of Wallington if this is the standard of their work!
Suddenly the whole of the maths section seems to be flooded with inane questions. What's happening?
130 ounces is 8.1lb, or 3.7kg. It's the weight of a healthy new-born baby. A six-month old who weighed that would be regarded as seriously ill, so even if said newborn immediately went on holiday, it's unlikely s/he would want to end up in an ICU six months later.
The question might have said "pounds". 130 pounds is 9st4lb, or 59kg: a small woman's weight. Except no-one in the UK would refer to their weight in pounds: it's an American thing, as they don't use stone.
And, as others point out, the question has an infinite number of answers. Say she gained 10 on holiday. She weighed 128 before she left. Say she gained 20 on holiday. She weighed 126 before she left. before = 130 - (0.2 x gain): two unknowns, and you only have one equation.
Like aaman1, we're either being fed homework, or mis-remembered questions.