The ratio of the distances a 7-iron and a 5-iron will drive a golf ball is 5 to 6. If a golfer averages 166 yards with a 7-iron, how far should he average with a 5-iron?

166/x = 5/6

To find out how far the golfer should average with a 5-iron, we can use the ratio given between the distances of the two clubs.

Let's set up a proportion using the given information:

(7-iron distance) / (5-iron distance) = (7-iron average distance) / (5-iron average distance)

The ratio of the distances is given as 5 to 6, so we can substitute those values:

5 / 6 = 166 / (5-iron average distance)

To solve for the 5-iron average distance, we can cross-multiply:

5 * (5-iron average distance) = 6 * 166

Now, let's solve for the 5-iron average distance:

25 * (5-iron average distance) = 996

Dividing both sides by 25, we get:

5-iron average distance = 996 / 25

Calculating the division, we find:

5-iron average distance ≈ 39.84 yards

Therefore, the golfer should average approximately 39.84 yards with a 5-iron.