In a survey of teenagers, 2/3 responded that they got regular exercise, and 4/5 of those said that walking was their main form of exercise. What fraction of the teenagers mainly exercise by walking?(
To find the fraction of teenagers who mainly exercise by walking, we can multiply the fractions together:
2/3 * 4/5 = (2 * 4)/(3 * 5) = 8/15.
Therefore, 8/15 of the teenagers mainly exercise by walking.