Answer
$P(all~3~have~driven~while~under~the~influence~ of~alcohol)=0.024389$
Work Step by Step
$29$% $=0.29$
The events "21- to 25-year-olds 1 has driven while under the influence of alcohol", "21- to 25-year-olds 2 has driven while under the influence of alcohol" and "21- to 25-year-olds 3 has driven while under the influence of alcohol" are independent.
Using the Multiplication Rule for Independent Events (pag 282):
$P(all~3~have~driven~while~under~the~influence~ of~alcohol)=P(21- to~25-year-olds~1~has~driven~while~under~the~influence~of~alcohol)\times P(21- to~25-year-olds~1~has~driven~while~under~the~influence~of~alcohol)\times P(21- to~25-year-olds~1~has~driven~while~under~the~influence~of~alcohol)=0.29\times0.29\times0.29=0.024389$
