Accounts payable – (Early Payment Discount)

Greetings Tutor I hope you are doing well, can you help me with the following-

1) There is an Example on Study Hub (16.5.1 Trade Credit as a Source of Finance), which explains Early Payment Discount.

Ex — Alanis purchases $5,000 of goods from Celine. Celine offers all customers the option of either 30 days’ credit or a 1.5% discount if cash is received in five days. If Alanis takes the cash discount, she will incur an overdraft on which interest is charged at 20% a year. Is the cash discount beneficial to Alanis?

Solution, If Alanis takes the cash discount, she will save $5,000 * 1.5% = $75.
However, she will incur an overdraft for an additional 25 days (30 – 5 days), which will cost $67.47 ($4,925 [amount paid] × [20% × 25/365])
Alanis will benefit by $7.53 if she pays the invoice within 5 days.

2) While a similar question in Kaplan’s Study Text.
Ex – One supplier has offered a discount to Box Co of 2% on an invoice for $7,500, if payment is made within one month, rather than the three months normally taken to pay. If Box’s overdraft rate is 10% per year, is it financially worthwhile for them to accept the discount and pay early?

Solution
Discount saves 2% of $7,500 = $150.
Financed by overdraft for extra two months in order to pay early:
Overdraft fee saved if discount not accepted: $7,500 × 10% × 3/12 = $187.50
Overdraft fee saved if discount accepted: ($7,500 – $150) × 10% × 1/12 = $61.25 Saving lost = $187.50 – $61.25 = $126.25.
Net saving = $150 – $126.25 = $23.75 It is worth accepting the discount.

Although both the question seems to be of similar style, but the way of doing them are different and therefore, giving different Net Savings. Can you tell me which method should be followed. I did watched your video, but both the examples in there has been explained through computation of Effective Annualised Cost of Discounting.