Question

what is 17.5 per cent of two thousand four hundred pounds.

Answer 1

that implies a simple multiplication, with a couple considerations:
17.5 percent = 17.5% = 17.5/100 = 175/1000
so we multiply both quantities:
17.5% of 2400
= (17.5%)(2400)
= (175/1000)(2400)
= 175*2400/1000
= 420