4/10 is surprisingly low. Most of us would borrow to pay a $400 emergency expense. Are there really that many people out there paying with cash or check instead of “borrowing” by paying with credit card?
The question is not if you're carrying $400 in cash, but whether you can afford that expense. A credit card paid off in full is considered cash-equivalent: "When faced with a hypothetical expense of only $400, 59 percent of adults in 2017 say they could easily cover it, using entirely cash, savings, or a credit card paid off at the next statement (referred to, altogether, as “cash or its equivalent”)" (from the same page of that report).
The technicality of making the payment by cash or cc is beside the point, the point was that there is not 400 of savings available to immediately pay down the CC
I've read 4/10 a couple of times now, and all I hear is my math teacher yelling "reduce your fraction".
Me too, but when I think of 2/5, it is a little harder to picture. I don't know if that's just because I already let 4/10 get into my head though.