Fifteen houses are located in a row such that the distance between two adjacent houses is equal. If the distance between the 1st and 15th house is 560 ft, then what is the distance between the 3rd and 7th house?

Correct option is C

Given:

Distance between 1st and 15th house = 560 ft.
Formula Used:

Distance between nth and (n + m)th house = (m-1) × Distance between adjacent houses

Solution:

Distance between adjacent houses = $$\frac{560\ ft}{ (15-1)}$$​= 40 ft.

Distance between 3rd and 7th house = (7-3-1) × 40 ft. = 160 ft

Hence, the correct answer is (c).