Notes, summaries, assignments, exams, and problems for Mathematics

Critical Path Method (CPM) vs. PERT

HL (time to completion may be delayed without affecting the beginning of another and final term), HM (the worst case of free float.) Critical path: the path of longer duration and is defined by the sequence of activities that mark critical events in the network. These activities are styled with a double arrow. An activity is critical when it has no slack time, and an event is critical when its TE (earliest time) and TL (latest time) are equal. We must pay critical attention to these routes, as any delay may affect the entire project. Beginning and ending events are critical.

PERT (Program Evaluation Review Technique): It is a probabilistic system that assigns each possible activity three durations: pessimistic,... Continue reading "Critical Path Method (CPM) vs. Program Evaluation Review Technique (PERT)" »

Levels of Number Understanding

Level 1

At this level, number figures are symbols linked to real-world objects.

Level 2

Children try to find correspondence between written figures and quantitative aspects of objects.

Level 3

Numbers, especially single-digit numbers, represent counts of objects. Two-digit numbers are not yet seen as composed of constituent figures.

Level 4

Two-digit numbers systematically represent the total quantity, but each digit is treated as a separate number without understanding place value. For example, in 16, '6' might represent six objects and '1' might represent one object. Alternatively, '6' might represent sets of 6, and '1' might relate to a single unit or group.

Level 5

Each digit in a two-digit number represents an amount... Continue reading "Key Concepts in Math Education" »

Special Corporate Tax Regimes in Spain

This document outlines key special tax regimes under the Spanish Corporate Tax Law (TRLIS), offering significant benefits for eligible businesses.

Tax Benefits for Small Companies (TRLIS Articles 108-114)

This regime applies to companies with a turnover below €10 million in the previous year. Key consequences include:

• Reduced Tax Rates:
  • 25% for the first €300,000 of taxable base.
  • 30% for the remainder of the taxable base.
• Accelerated Depreciation:
  • For fixed assets, the maximum depreciation rate is multiplied by 2.
  • For intangible assets, the maximum repayment rate is generally multiplied by 2.
  • In case of asset reinvestment (Article 113 TRLIS), the maximum repayment rate is multiplied by 3.
• Provision for Doubtful

Fundamental Geometric Concepts

Basic Geometric Elements

• Line: A straight path without beginning or end, extending infinitely in both directions.
• Ray: A straight path that has a beginning point but no end, extending infinitely in one direction.
• Segment: A straight path delimited by two distinct endpoints.
• Angle: The opening formed by two rays that share a common starting point (vertex).

Relationships Between Lines

• Intersecting Lines (Secant): Lines that cross each other at a single point.
• Parallel Lines: Lines that lie in the same plane and never intersect, having nothing in common.
• Coincident Lines: Lines that occupy the exact same position, sharing all points in common.
• Perpendicular Lines: Lines that intersect to form four equal (90-degree) angles,

Exercise 1: Calculating Monthly Interest Rate

A person invested $12,000 in an institution and received $13,008.00 after seven months. What is the equivalent monthly interest rate that the investor earned?

Solution:

• Initial Capital (C) = $12,000
• Time (n) = 7 months
• Future Value (FV) = $13,008.00

Using the formula: FV / C = (1 + i * n)

13,008.00 / 12,000.00 = (1 + i * 7)

1. 0840 = 1 + 7i

2. 0840 = 7i

i = 0.0840 / 7

i = 0.012 or 1.2% per month

Exercise 2: Equivalent Financial Return

An investment of $15,000 is made for a period of three months at a simple interest rate of 26% per annum. What amount must be invested for two months at a linear rate of 18% per year to achieve the same financial return?

Solution:

Investment 1:

• C = $15,000
• n = 3 months
• i (annual)

Direct Methods

1a) Gauss Elimination Method

The Gauss Elimination method consists of converting a matrix into an equivalent matrix with zeros below the main diagonal of A. The first equation will have n variables, the second n-1, and so on until the final equation, which will have only one variable. Once the zeros are achieved, the values of the variables are found by starting with the last variable and substituting back up to the first. This solves the system.

1b) Gauss-Jordan Method

The Gauss-Jordan method consists of obtaining a diagonal matrix instead of just an upper triangular matrix. Variables are obtained directly from the resulting system, without substitutions. This saving in the final step comes at the cost of slightly increasing the... Continue reading "Direct and Indirect Methods: Gauss and Jacobi" »

Essential Language and Literary Concepts

Vocabulary Definitions

• Ratification: To confirm something is true or valid.
• Sullen: Bad-tempered and sulky; gloomy.
• Persuade: To induce someone to do something through reasoning or argument.
• Obey: To comply with a command, instruction, or law.
• Prescribed: To lay down as a rule or course of action to be followed; to determine.
• Literal: Taking words in their most basic sense without metaphor or allegory.
• Prolific: Producing much fruit, foliage, or many offspring; producing many works.
• Clause: A distinct article or provision in a document, such as a contract or law.
• Maize: A cereal grain, especially corn, that is already mature.
• Diligence: Careful and persistent work or effort.
• Ninety: The cardinal number equivalent

Troubleshooting Bibliographic Reference

Daniel Robert Sippe & Bulfin: Planning and Production Control, Chapter 3

Troubleshooting Problem Definition

Problem: When I expect something to happen and it does not.

Approaches to Resolution

How to Solve:

1. Acquittal: Ignore the issue.
2. Resolution: Use common sense.
3. Solution: Use the USA method (the best answer).
4. Dissolution: Redesign to eliminate the cause.

Participation in the Problem

Who is involved:

• Owners of the Problem: Those who interact with and live with the problem.
• Analysts: Those who study the solutions.

Focus: The Six-Step Problem Solving Process

Step 1: Identification of the Problem

1. Owners of the Problem
2. Analyst
3. Need / Opportunity
4. Overall Purpose:
   • Levels
   • Goals
   • Objectives
5. Assumptions

Step 2: Understanding the

Parties Involved in a Bill of Exchange

The issuance and circulation of a bill of exchange involves the following parties:

• The Drawer: The creditor who issues the bill of exchange, instructing the debtor to pay.
• The Drawee: The debtor who is obligated to pay the bill of exchange at maturity. The drawee may accept or reject the payment order. If accepted, the drawee becomes the acceptor.
• The Payee/Holder/Beneficiary: The person who holds the bill of exchange and is entitled to receive payment.

Form of Bills of Exchange

A bill of exchange must be issued on official forms or stamped paper issued by the State. The amount should be proportional to the value stated on the bill. Improper formatting may cause difficulties in pursuing action against the debtor... Continue reading "Understanding Bills of Exchange: Parties, Form, and Accounting" »