1.  A sum of ₹ 1550 was lent partly at 5% and partly at 8% p.a. simple interest. The total interest received after 3 years was ₹ 300. The ratio of money lent at 5% to that lent at 8% is :
A. 5 : 8
B. 8 : 5
C. 16 : 15
D. 31 : 6

Answer: Option C

Explanation:

Let the sum lent at 5% be ₹ X and that lent at 8% be ₹ (1550 - X). Then,

X x 5 x 3 + (1550 - X) x 8 x 3
100 100

<=> 15X - 24X + (1550 x24) = 30000
<=> 9X = 7200
<=> X = 800.
Required ratio = 800 : 750 = 16 : 15