Answer:
Principle for account B is greater.
Step-by-step explanation:
First of all, let us have a look at the formula for Simple Interest:
[tex]SI =\dfrac{PRT}{100}[/tex]
Where [tex]P[/tex] is the principle amount
[tex]R[/tex] is the Rate of interest per annum
[tex]T[/tex] is the time in years.
Time = 21 months = [tex]\frac{21}{12}\ yrs[/tex]
[tex]R_1 = 3\% \\R_2=4\%[/tex]
Let the Principles be [tex]P_1, P_2[/tex].
Using the formula for Simple Interest, we get:
[tex]SI_1=\dfrac{P_1\times 3\times 21}{100\times 12}\\\Rightarrow 15.75=\dfrac{P_1\times 3\times 21}{100\times 12}\\\Rightarrow P_1 = 300[/tex]
[tex]SI_2=\dfrac{P_2\times 4\times 21}{100\times 12}\\\Rightarrow 28=\dfrac{P_2\times 3\times 21}{100\times 12}\\\Rightarrow P_2 = 533.33[/tex]
Therefore, principle for account B is greater.
