Evaluate the triple integral B
xyz2 dV,
where B is the rectangular box
B =

(x, y, z) | 0 ≤ x ≤ 1, −1 ≤ y ≤ 7, 0 ≤ z ≤ 4

,
integrating first with respect to y, then z, and then x.

Each face of the box B is described completely by a single variable, so the value of the integral is independent of the order of integration.

The integral in question would be

but we can factorize the integral as

We can do this regardless of the order of integration we choose. Then

and the triple integral has a value of

But, if you insist on carrying out just one integral at a time, we have

well if he bought them at 5 cedis each sold them at 7 cedis each then he would make a profit of 2 cedis of each book. if in total he made 150 cedis profit that means he sold 75 books. he lost 12 books at the start so that means he originally bought a total of 82 books.

step-by-step explanation: