/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 40 A person can memorize at most 40... [FREE SOLUTION] | 91Ó°ÊÓ

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A person can memorize at most 40 two-digit numbers. If that person can memorize 15 numbers in the first 20 minutes, find a formula for the number that can be memorized in \(t\) minutes. Use your answer to estimate how long the person will take to memorize 30 numbers.

Short Answer

Expert verified
It will take 40 minutes to memorize 30 numbers.

Step by step solution

01

Understand the Variables

Let the number of two-digit numbers the person can memorize in \(t\) minutes be \(N(t)\). We know that the maximum a person can memorize is 40 numbers, and they memorize 15 numbers in the first 20 minutes.
02

Assume Linear Relationship

We assume that the rate of memorization is constant, meaning the number of numbers memorized per minute is consistent. Thus, the relation between time \(t\) and numbers memorized \(N(t)\) can be expressed as a linear equation in the form \(N(t) = mt + c\), where \(m\) is the rate of memorization and \(c\) is the initial amount memorized.
03

Calculate the Memorization Rate

Given that in 20 minutes, 15 numbers are memorized, we set up the equation \(15 = 20m + c\). Since initially (at \(t=0\)), the person knows 0 numbers, \(c = 0\). Thus, the rate \(m\) becomes \(m = \frac{15}{20} = 0.75\).
04

Establish the Memorization Formula

Substituting \(m\) and \(c\) back into the linear equation \(N(t) = mt + c\), we have the formula \(N(t) = 0.75t\). This represents the number of numbers the person can memorize in \(t\) minutes.
05

Estimate time to Memorize 30 Numbers

To find the time \(t\) needed to memorize 30 numbers, set \(N(t) = 30\). Plug this value into the equation: \(30 = 0.75t\). Solving for \(t\) gives \(t = \frac{30}{0.75} = 40\).
06

Verify Constraints

Check if the formula satisfies the condition of memorizing up to 40 numbers. Using the formula, \(N(40) = 0.75 imes 40 = 30\), which is under the max and consistent with behavior up to that point. Memorizing 40 numbers would require over 53 minutes, indicating the model's validity within its intended range.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Memorization Rate
The memorization rate is a crucial factor when determining how quickly someone can learn or remember information over time. In this scenario, we relate time in minutes to the number of two-digit numbers retained. The rate is represented as a constant, assuming a straight-line progression.
This problem provides key insights: that in 20 minutes, 15 numbers are memorized. This consistent progress suggests a constant rate, forming the basis of a linear function.

Using the information given, the memorization rate (\(m\)) is calculated as follows: - Memorized numbers: 15- Time: 20 minutes

To find \(m\), the formula for the rate is \(m = \frac{15}{20} = 0.75\).

This means every minute, the person remembers, on average, 0.75 numbers. This steady pace is integral in predicting future memorization capabilities within specific timeframes.
Maximum Memorization
Not everyone can memorize an infinite number of items. In this exercise, 40 two-digit numbers represent the upper bound of memorization capacity. This limit must be considered when setting expectations and formulating predictions about memorization ability.Understanding maximum memorization involves acknowledging that even with a steady learning pace, capacity constraints eventually come into play. These may be influenced by distractions or mental fatigue, leading to flawed assumptions if not factored into models.When reviewing formula outcomes, such as \(N(t) = 0.75t\), students must check if predictions exceed this memorization limit. The problem candidly includes this constraint, warning that you should verify results to ensure they align with tangible human capacities. It's a great practice to consider this before applying a theoretical math model to real-world scenarios.
Linear Relationship
A linear relationship describes a proportional link between two variables, maintaining a consistent rate of change. Here, the relationship between time spent memorizing and the numbers learned is linear. This means, as both increase, they do so in a straightforward and predictable manner, forming a line when graphed.Why assume linearity here? Because the scenario suggests a constant memorization rate without interruption or slowdown. The rate (\(m\)) translates over time into accumulated knowledge, modeled as \(N(t) = mt + c\), with \(c\) as initial memorization.- For simplicity, assume initial memorized number \(c\) is 0.To determine how long it takes to memorize a set number, like 30 numbers, plug it into \(N(t) = 0.75t\). This approach showcases the utility of linear equations to make predictions. Yet, always verify assumptions to ensure they're applicable within understood constraints, like our calculated "within 40 number maximum" range.

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