Correct Answer - Option 4 : 2 : 3
Solution:
Given: Bharti has money at interest rate = 5%
Swati has money at interest rate = 10%
Overall interest rate gain by Aarti = 8%
Concept used: {Amount lent to Bharti × (rate/100)} + {Amount lent to Swati × (rate/100)} = {(Amount lent to Bharti + Amount lent to Swati) × (rate/100)}
Calculation: Let the money lent to Bharti is ‘x’ and money lent to Swati is ‘y’.
Then, {x × (5/100)} + {y × (10/100)} = {(x + y) × (8/100)}
⇒ (5x/100) + (10y/100) = (8x/100) + (8y/100)
⇒ (8x – 5x)/100 = (10y – 8y)/100
⇒ 3x = 2y
⇒ x/y = 2/3
∴ Aarti has lent the money to Bharti ad Swati in the ratio 2 : 3.