Guest lectures on five subjects viz., Economics, History, Statistics, English and Mathematics have to be arranged in a week from Monday to Friday. Only one lecture can be arranged on each day. Economics cannot be scheduled on Tuesday. Guest faculty for History is available only on Tuesday. Mathematics lecture has to be scheduled immediately after the day of Economics lecture. English lecture has to be scheduled immediately before the day of Economics lecture.

To determine which lecture is scheduled on Monday, we need to correctly arrange the schedule based on the given constraints. Here's the step-by-step reasoning:

1. The lecture schedule is from Monday to Friday with one subject per day: Economics, History, Statistics, English, Mathematics.
2. From the information given, History can only be scheduled on Tuesday. Thus:1. Economics cannot be scheduled on Tuesday, which we already know, nor can it be scheduled on Thursday.
2. English must be scheduled immediately before Economics, so if we try to place Economics on Wednesday, English must be on Tuesday. However, History is on Tuesday, so this leaves only Friday as the feasible option for Economics with English on Thursday.1. Now, Mathematics has to be scheduled immediately after Economics, but since Mathematics is generally a sequential context, the only choice left for Mathematics is on Wednesday.
2. This leaves Statistics for Monday.Therefore, the lecture scheduled on Monday is Statistics.