How much should you invest at 4% simple interest in order to earn $50 interest in 6 months

Simple interest formula
Interest = Pit = $50
P=principal (initial investment)
i=annual interest rate = 0.04
t=time in years = 6 months = 0.5 years

Substitute values,
$50 = P*0.04*0.5 
Solve for P
P=$50/(0.04*0.5)=$2500

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)