SI=160

TIME=2 YEAR

CI=164

So,

SI= PRT/100

160=PR*2/100

PR=8000...........(i equation)

NEXT

CI=P(1+R/100)^2-P

TAKE P COMMON

164=P((1+R/100)^2-1)........(ii equation)

Divide first equation by second equation

8000/164=(PR)/P((1+R/100)^2-1)

2000/41=R/(1+R/100)^2-1

CROSS MULTIPLICATION

2000*{(1+R/100)^2-1}= 41R

Open bracket

2000*(1+R^2/10000+2R/100-1)=41R

Gives

2000*(R^2/10000+2R/100)=41R

(R^2)/5+40R= 41R

Cancel one R

(R/5)+40=41

R/5=41-40

R/5=1

R=5%

Ans RATE = 5%