Pankaj invests an amount by dividing it between three different schemes A, B and C with rates of interest, 10% 12% and 15% per annum respectively, and the total interest that accumulates in one year is ₹3200. The amount he invests in schemes A, B and C are in the proportion 8 : 5 : 12, then what is the amount he invests in scheme B?

₹5000

Amount invested in scheme A , B & C are in ratio 8 : 5 : 12 .

We know ,

Simple Interest = \(\frac{Principal ×Rate × Time }{100}\)

\(\frac{8x × 10 × 1 }{100}\) + \(\frac{5x × 12 × 1 }{100}\) + \(\frac{12x × 15 × 1 }{100}\) = 3200

\(\frac{4x }{5}\) + \(\frac{6x }{10}\) + \(\frac{9x }{5}\) = 3200

\(\frac{8x  + 6x + 18x}{10}\)= 3200

32x = 32000

x = 1000

Amount invested in scheme B = 5x = 5 × 1000  = Rs. 5000