Starting money = $350.
interest rate = 2.5%
time = 3 years.
how much interest?

The interest earn at simple interest is $26.25

The interest earn at compound interest is $26.88

Step-by-step explanation:

Given as :

The principal money = p = $350

The interest rate = r = 2.5 %

The time period = t = 3 years

Let the interest = S.I

From Simple Interest method

Simple Interest =

Or, S.I =  

Or, S.I =  

Or, S.I = = $ 26.25

Hence The interest earn is $26.25

From Compound Interest method

Amount = Principal ×

Or, Amount = $350 ×

Or, Amount = $350 × (1.025)³

Or, Amount = $350 × 1.0768

∴ Amount = $376.88

Now, Interest = Amount - principal

So, Interest = $376.88 - $350

Or, Interest = $26.88

Hence The interest earn is $26.88

Answer

b. astronomers

a² + b²= c²

24² + 7² = c²

c= 25