27) B
1 – Correct
Percentage of 17-34 year olds = 30%
Percentage that travel by walking or public transport = 10 + 15 = 25%
Even if we assume that all those who travel by walk/cycle are 17-34 year olds, then the remaining 5% must travel by car and 5% is (¹⁄₆) of 30%.
2 – Correct
Half of percentage of under 16s = ³⁰⁄₂ = 15%
Number which travel by public transport = 15%
If we assume that all those who take public transport are under 16, then the maximum that can use the public transport is 15% of under 16s which is no more than half of the total 30%.
3 – Wrong
Percentage of 60 and above = 15%
Percentage 60 and under = 100 – 15 = 85%
Percentage which are not walking or cycling = 100 – 10 = 90%
Since 85 % can fit in 90%, we cannot know for sure that some 60 and under people either walk or cycle.