We are giving the volume of a prism as 1001 in^3
We know that the volume of a prism is defined as the product:
Volume = length x height x width
And we are asked to find the length given that the height is 13 and its width is 7. Then, we replace all this values in the formula and solve for the unknown:
1001 = length x 13 x 7
1001 = length x 91
divide both sides by 91 to isolate the length completely
1001 / 91 = length
11 = length
Then the length is 11 in.