A 20-year 10% Rs 1,000 bond that pays interest half-yearly is redeemable (callable) in twelve years at a buy-back (call) price of Rs 1,150. The bonds current yield to maturity is 9.50% annually. You are required to determine (i) the yield to call, (ii) the yield to call if the buy-back price is only Rs 1,100, and (iii) the yield to call if instead of twelve years the bond can be called in eight years, buy-back price being Rs 1,150.