2.5$:100%=x:20%, This ratio is calculating by multiplying inertal members and that is equal to external members. 100%*x=2.5$*20%, x= 2.5*20/100, x=0.5$ is 20% of 2.5$. So for 1st book you will save 0.5$.
4.95$:100%=x:20%, x=0.99$ is 20% of 4.95$. For 2nd book you will save 0.99$
6$:100%=x:20%, x=1.2$ is 20% of 6$. For 3rd book you will save 1.2$. All in total you will save 2.69$.
2. Total coast of items: 2.5$+8.75$+3+10.25$=24.5$. The tax rate is 6%. 24.5$:100%=x$:6%, x*100=24.5*6, x=24.5*6/100, x=1.47$ Tax is 1.47$.
