Item 10 find the amount of time. i=$450, p=$2400, r=7.5%

The answer is:  "2.5 years" . 

  Note:   I = P * r * t  ;    { " Interest = Principal * rate * time "} ; 

          →     Solve for "t" {"time", in years} ;  

Divide each side of the equation by "{P * r}"  ;  
   to isolate "t" on one side of the equation ;

→  I / (P * r)  = {P * r * t) / (P * r} ; 

to get:  " I / (P * r) = t " ;  

  ↔  t = I / (P * r) ; 

Given:  I = $450 ;  
  
            P = $2400 ; 

            r = 7.5% = 7.5/100 = 0.075 ; 

Plug in these values into the formula to solve for the time, "t" :

        →  t  =  I  /  (P  *  r )   ;  

                 =  $450  /   ($2400 * 0.075) ;

                 =  $450  /   ($2400 * 0.075) ;

                 =  $450 / $180 ; 

                 =  $45 / $18 ; 

                 =  ($45 ÷ 9) / ($18 ÷ 9) 

                 =  $5 / $2 ; 

                 =  2.5  ; 

        →  t  =  2.5 years.

The answer is:  "2.5 years" .