11) C

Women carried out an overall average of 60% more unpaid work than men.
Value of total unpaid work = £1000 billion
We can make up an equation to state this. Let ‘Y’ be value of unpaid work carried out by men.
Value of unpaid work by women = 160% x Y= 1.6Y

Y + 1.6Y = £1000 billion
2.6Y = £1000 billion
(Taking 2.6 ≈ 2.5),
Y = 400 billion
Women did = 1000 – 400 = £600 billion worth of unpaid work.

The actual value would be higher as we rounded 2.6 to 2.5 so C (£615 billion) is the answer.