Answer:
40 blocks
Explanation:
Imagine the city is placed on a Cartesian plane grid or graph. The streets count rightwards and avenues count upwards.
Each location can be written as a coordinate or ordered pair in the form (x, y). "x" is the street number and "y" is the avenue number.
Jerome Walker lives at 3rd St. and 24th Ave. He lives at (3, 24).
The bank at 3rd St. and 11th Ave. is at (3, 11).
The post office at 10th St. and 11th Ave. is at (10, 11).
The barbershop at 10th St. and 24th Ave. is at (10, 24).
And again, his home is at (3, 24).
Calculate the number of blocks, or squares on the grid, between each part of his walk. Then, add the numbers together.
(3, 24) to (3, 11): 24-11 = 13
(3, 11) to (10, 11): 10-3 = 7
(10, 11) to (10, 24): 24-11 = 13
(10, 24) to (3, 24): 10-3 = 7
13 + 7 + 13 + 7 = 40
Therefore Jerome Walker walked 40 blocks.