Amarketing firm randomly sends a mass promotional mailing to 21 %of the households in a new market area. from experience the firm knows that the probability of response to a mailing is 0.14 number .what is the probability that a household receives the mailing and responds?

Let X be the number of households. 

so they sent the promotional material to 21% which means 0.21X number of households get the material. 

out of the 0.21x households only 0.14 respond which is 

0.14(0.21x) = 0.0294x or 2.94%

2.94% is the probability that a household receives and responds.