By what age will children show a preference for a small group of playmates?

According to the text, about what percentage of cohabiting couples in the U. S. today are over the age of 40:

a. about 10% b. about 20% c. about 35% d. about 70%

The goal of program evaluation is to judge the utility or value of educational, psychological, or

social intervention programs. Indicate whether the statement is true or false