4.—(1) The national minimum wage is the single hourly rate of—
(a)£6.50 for a worker who is aged 21 years or over;
(b)£5.13 for a worker who is aged 18 years or over (but is not yet aged 21 years);
(c)£3.79 for a worker who is aged under 18 years;
(d)£2.73 for a worker to whom the apprenticeship rate applies, as determined in accordance with regulation 5.
(2) The single hourly rate of the national minimum wage at which a worker is entitled to be remunerated as respects work, in a pay reference period, is the rate which applies to the worker on the first day of that period.
(3) If the rate in paragraph (1)(d) applies to a worker, the rates in paragraph (1)(a), (b) and (c) do not apply to that worker.