I think a video explanation explains it well.

https://www.gmatquantum.com/list-of-vide ... ds130.html

Have a look!

Thanks shankar.ashwin. The video was really useful!

nidhis.1408 wrote:If juan had a doctor's appointment on a certain day, was the appointment on a wednesday?

1. Exactly 60 hours before the appointment, it was monday.
2. The appointment was between 1 pm and 9 pm.

This question id from OG page-284, question no-130.
I need a simpler and better explanation

thanks

Was the appointment on Wednesday?

1. 60 hours before the appointment, it was monday

Which means that 2.5 days earlier it was monday---- since 60/24 is 2.5

now lets count from noon Monday

12:00 Monday plus 24 is 12:00 Tuesday
12:00 Tuesday plus 24 is 12:00 Wednesday
12:00 Wednesday + 12 is 24:00 Wednesday (Right at the Cusp of Wednesday and Thursday)

The above information clearly tells us that we need to the time of the appointment so Statement 1 is not sufficient

2. Statement 2 is obviously insufficient because there is no reference to the day.

Combining Both:

We know that the appointment was not on Wednesday since for it to be on Wednesday it had to be before Noon !