The diagram gives percentages of a group who like three radio stations; 140 people like exactly one station. How many like all three?

Exactly one $=16+14+10=40\%$, so 40% is 140 people and the group has 350. All three $=6\%$ of 350 $=21$. 6 is the percentage, 84 is the exactly-two group (24%), and 35 is the 10% who like only the third station.