Chapter 7, Problem 34CP

a.

To determine

To copy:And complete the table.

Answer to Problem 34CP

The required table is given below.

Explanation of Solution

Given:

Your,

Principle amount - $500

Simple interest annually − 3%

Your friend,

Principle amount - $400

Simple interest annually − 5%

Formula used:

Amount = P + PRT

= P(1+RT)

Calculation:

The required table is given below.

  

b.

To determine

To write:An expression for each account balance after $x$ years.

Answer to Problem 34CP

An expression for each account balance after $x$ yearsis,

Your account balance $=500\left(1+0.03x\right)$

Your friend account balance $=400\left(1+0.05x\right)$

Explanation of Solution

Given:

Your,

Principle amount - $500

Simple interest annually − 3%

Your friend,

Principle amount - $400

Simple interest annually − 5%

Formula used:

Amount = P + PRT

= P(1+RT)

Calculation:

Therefore,

An expression for each account balance after $x$ yearsis,

Your account balance $=500\left(1+0.03x\right)$

Your friend account balance $=400\left(1+0.05x\right)$

Hence, expression for each account balance after $x$ yearsis

  $500\left(1+0.03x\right)$ and $400\left(1+0.05x\right)$ .

c.

To determine

To find:The number of years taken by your friend’s balance to equal your balance is 8 years.

Answer to Problem 34CP

The probability of choosing two numbers whose sum is even increases.

Explanation of Solution

Given:

Your,

Principle amount - $500

Simple interest annually − 3%

Your friend,

Principle amount - $400

Simple interest annually − 5%

Since, after 8 years

Your friends balance is

  $\begin{array}{l}=400\left(1+0.05\times 8\right)\\ =560\end{array}$

Hence, the number of years taken by your friend’s balance to equal your balance is 8 years.