Inverting equity to assets for Dupont

CFA Level I FRA
#1

From Kaplan:

A company has a net profit margin of 4%, asset turnover of 2.0, and a debt-to-assets ratio of 60%. What is the ROE?

Answer: Debt-to-assets = 60%, which means equity to assets is 40%; this implies assets to equity (the leverage ratio) is 1 / 0.4 = 2.5

Why do we invert 40% to 1 / 0.40 = 2.5? I know this is a simple algebra question but I am remiss in the reasoning.

#2
\frac{Equity}{Assets} = 40\% = 0.40
Equity = 0.40\times Assets
\frac{Equity}{0.40} = Assets
Assets = \frac{Equity}{0.40}
\frac{Assets}{Equity} = \frac{1}{0.40} = 2.5
#3

Perfect explanation, thank you.

#4

My pleasure.