Suki invested $12,000 at 5% and $8,000 at 10%
Explanation:
- Step 1: Principal = $20,000, Interest 1 Rate, R1 = 5% and Interest 2 Rate, R2 = 10%, Time = 1 year and total interest = $1400
Let the amount invested at R1 be P1 and that invested at R2 be 20000 - P1
⇒ Total Interest = P1×R1×T/100 + (20000 - P1)×R2×T/100 (since Simple Interest = PRT/100)
⇒ Total Interest = T/100 [P1R1 + (20000 - P1)R2] (Taking out the common factors)
⇒ 1400 = 1/100 (5P1 + 20,000 × 10 - 10P1)
⇒ 140,000 = -5P1 + 200,000
⇒ 5P1 = 60,000
⇒ P1 = 60,000/5 = $12,000
⇒ P2 = 20,000 - P1 = $8,000