Question

An investment of d dollars at k percent simple annual interest yields $600 interest over a 2-year period. In terms of d, what dollar amount invested at the same rate will yield $2,400 interest over a 3-year period?

Answer 1

so amount is 8d / 3 or 2.667 d

Step-by-step explanation:

given data

invest amount = $d

rate r = k%

interest = $600

time t = 2 year

to find out

amount invested with interest #2400 for 3 year

solution

we will apply here interest formula that is

interest = principal × rate × time / 100 ........................1

put here value we get 2 equation

600 = ( d × k × 2 ) / 100 ..............a

dk = 30000 ...................2

and for 2400 interest for 3 year

2400 = ( amount × k × 3 ) / 100 ................b

amount × k = 80000 .....................3

so from equation 2 and 3

amount × (3000/d) = 80000

amount = 8d / 3

so amount is 8d / 3