If Martin deposited \$2,11 into an account and earned $750 of interest over 5 years, how much was the interest rate?

5.90% much was the interest rate .

Step-by-step explanation:

Here we have , If Martin deposited \$211 into an account and earned $750 of interest over 5 years, We need to find how much was the interest rate . Let's find out:

Let us suppose that interest rate was x%  per month! So , Amount of money he earned as interest per month :

⇒

Now , For one year( 12 months ) he earned :

⇒

∴For five year he earned :

⇒

According to question , he earned $750 of interest over 5 years i.e.

⇒

⇒

⇒

⇒

Therefore , 5.90% much was the interest rate .

The interest rate is 7.1%

Step-by-step explanation:

It is given that,

To find the interest rate :

The formula used here is given by,

Interest = P× r× t

where,

Now, substituting P= $211 , t= 5 and  I = $750

⇒ 750 = 2110 × 5 × r

⇒ 750 = (10550×r)

⇒ 750 ÷ 10550 = r

⇒ r = 0.071

The rate should be represented in the percentage, therefore,  multiply it by 100.

Interest rate = 0.071 × 100

Rate = 7.1 %

∴ The interest rate is 7.1%

step-by-step explanation:

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50