Random quant problem under “solve problems” on website

Where did we get the 1.04 value for quantity a? The question just states it’s denoted by x. So is it safe to assume x^9 will be less than (1.04)^12x? When solving the problem Greg also assigned the amount 1.04 for quantity A



and that confused me.

4% more of x is 1.04x. Also this is simply a case of compounded interest - you don’t raise x, but 1.04. If this confuses you, consider what happens after 4 months, 8 months, and so on.

Also see the Compound Interest videos on PrepSwift.