The formula used to solve these problems is:
Principal × Interest Rate × Time = Simple Interest (the interest rate needs to be converted to a decimal and the time needs to be converted to years)
1) 2000 × 0.035 × 3 = $210
#6 and #12 are solved the same way
2) 1250 × _____ × 4 = 350
divide both sides by 1250 and by 4 --> 0.07 =
convert the decimal to a percent --> 0.07 = 7%
#5 & #11 are solved the same way
3) 500 × 0.045 × _____ = 157.50
divide both sides by 500 and by 0.045 --> 7 =
#8 and #10 are solved the same way
4) ______ × 0.05 × 4.5 = 2115
divide both sides by 0.05 and by 4.5 --> 940 =
#7 and #9 are solved the same way
See Table Below for answers: