First, work out the discounted price of the skateboard.
25% = 25
100 - 25 = 75
($130 × 75) ÷ 100 (to get the answer as a percentage) = $97.50.
If Josie has $90, you work out how much more she needs by doing $97.50 - $90, which is $7.50.
The answer is $7.50.