2. The publisher of a book sells to retailers on the following terms: Cash: \( 25 \% \) below published price, charging for 13 copies as 12 . 6 months credit: \( 29 \% \) below published price.
Calculate the effective rate of discount per annum that the publisher is allowing to retailers who pay cash. Express this as an effective rate of interest charged to retailers who accept the credit terms.
3. A loan of RI 000 is being repaid by level annual payments over a period of 10 years on the basis of interest of \( 5 \% \) p.a. for the first 5 years and \( 4 \frac{1}{1} \% \) p.a., for the second 5 years. Calculate the interest content of the 7 th annual payment.
4. Find at \( 5 \% \) p.a. effective the present value of an annuity-certain, payable annually in arrear for 40 years, under which successive payments are 4,7, 12, 19 etc. (Assume that payments are a quadratic function of time).