Type the formula that prices a 91-day T-bill quoted at 4.20 %, per 100 of face.

Answer

=100/(1+0.042*91/365)

Simple interest for 91 of 365 days at 4.20 %, then discount 100 by it: 98.9637. Multiply by face/100 for the dollar cost.

IIAC, Canadian Conventions in Fixed Income Markets, Release 1.3 §1.4, §2.1, §10.10 (T-bills priced at a simple-interest discount on actual/365) — observed 2026-09-17