Answer:
B) 1p - 0.4p
Explanation:
40% to a decimal is 0.4, so that immediately marks "A" and "C" wrong.
Now what you're trying to find is the expression itself, so you want to first look for keywords, 'cause sometimes they can just give away the answer.
"A" says you're multiplying (a variable beside a number means to multiply)
"B" says you're subtracting 1p (1 x p) and 0.4p (0.4 x p)
"D" says you're adding 1p (1 x p) and 0.4p (0.4 x p)
So, now you look over the question.
Really you can mark "A" wrong. Now it's just between "B" and "D."
When you use percentages and an item, you're taking it OFF the price. So, the answer is B.