A company's taxable total profits for the year to 30 June 2017 are £800,000. In the nine months to 31 March 2018 , the company incurs a trading loss of £700,000 and has no other income or gains. There are no Gift Aid donations in either period.

(a) Explain the corporation tax effects of a claim to relieve the trading loss against total profits.

(b) Calculate the effective rate of tax relief obtained in relation to the trading loss if such a claim is made.