To find Rate when Principal Interest and Time are given the rules are.



Interest = (Principal × Rate × Time)/100

Rate = (100 × Interest)/(Principal × Time)



Examples to find Rate when Principal, Interest and Time are given:

1. Find Rate, when Principal = $ 3000; Interest = $ 400; Time = 3 years.

Solution:

Principal = $ 3000,

Interest = $ 400,

Time = 3 years.

Rate = (100 × Interest)/(Principal × Time)

= (100 × 400)/(3000 × 3)

= 40000/9000

= 4.44 %

Therefore, Rate = 4.44 %.



2. Find Rate, when Principal = $ 2100; Interest = $ 350; Time = 2 years.

Solution:

Principal = $ 2100,

Interest = $ 350,

Time = 2 years.

Rate = (100 × Interest)/(Principal × Time)

= (100 × 350)/(2100 × 2)

= 35000/4200

= 8.33 %

Therefore, Rate = 8.33 %.



3. Find Rate, when Principal = $ 10000; Interest = $ 800; Time = 5 years.

Solution:

Principal = $ 10000,

Interest = $ 800,

Time = 5 years.

Rate = (100 × Interest)/(Principal × Time)

= (100 × 800)/(10000 × 5)

= 80000/50000

= 1.6 %

Therefore, Rate = 1.6 %.