Calculate the married couple's allowance available to the following couples in 2017-18, assuming that they were married before 5 December 2005 and that they have not elected for MCA to be claimed by the spouse with the higher net income:

(a) Husband born 1931, income £19,200; wife born 1932, income £29,500

(b) Husband born 1929, income £28,040; wife born 1934, income £10,070

(c) Husband born 1934, income £34,400; wife born 1939, income £20,000

(d) Husband born 1936, income £17,900; wife born 1933, income £46,700.

In each case, the stated income figure is the adjusted net income.