INR 6100/- was partly invested in Scheme A at 10% p.a. compound interest (compounded annually) for 2 years and partly in Scheme B at 10% p.a. simple interest for 4 years. Both the schemes  pay equal interests. How much was invested in Scheme A 

Let amount invested in Scheme A = INR x

Amount invested in Scheme B = INR (6100-x)

According to question,

x[(1+10/100)²-1 = (6100-x)×4×10/100

⇒ x[121/100-1] = (6100-x)×4×10/100

⇒ x[121-100/100]=(6100-x)×40/100

⇒ 21x=244000-40x

⇒ 61x=244000

⇒ x=INR 4000/-