The number of years that must be invested at a rate of 7 % to earn$ 303.52 in interest is
8 years
calculation
- by use of the formula A = P (1+ rt)
- where : A is the final amount = 542 + 303.52 =$ 845.52
P is the principal money to be invested = $ 542
r= rate= 7/100=0.07
t= time required
=$ 845.52=$ 542( 1+ 0.07 t)
- open the bracket
- = $845.53= $542 + $37.94 t
=$ 845.53 -$542 = $37.94 t
=$303.52 =$37.94 t
- divide both side by $37.94
= $303.52/ $ 37.94 = $37.94t/$37.94
t= 8 years
