Calculate the total amount and compound interest on rs 8,000 for a year at the rate of 9% per annum compounded half yearly.

See below in bold.

Step-by-step explanation:

Total  = A(1 + r/n)^nt   where A = initial amount , t = number of years, r = the rate (as a decimal fraction) and  n = number of payments a year. So:

Total after 1 year =  8000(1 + 0.09/2) ^ 1*2

= RS 8736.20.

Compound interest = RS 736.20

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.