Problem Solving

In a certain brick wall, each row of bricks above the bottom row contains one less brick than the row just below it. if there are 5 rows in all and a total of 15 bricks in the wall, how many bricks does the bottom row contain?

a.14
b.15
c.16
d.17
e.18

Say that the number of bricks in the bottom row is n. Then you have that there are n-1 bricks in the second row, n-2 in the third row, n-3 in the fourth row and n-4 in the fifth row. This means that you have a total of:
n + n - 1 + n - 2 + n - 3 + n - 4 = 5n - 10 bricks in your wall. We know that this is equal to 15, so you have the following equation:
5n - 10 = 15
5n = 25
n = 5.

I think you should check the answers... Or maybe I'm wrong....

I did it the exact same way. So if you are wrong then we both are wrong.

I am interested to hear if those are in fact the official answers.

i checked that the correct answer is D.

The question is wrong in wording or smth like this. If there are 15 bricks in the wall, how can the bottom row have 17 bricks? This means that the bottom row has more bricks than the entire wall, which is absurd.

I believe ther is typo in the question it should be 75 bricks instead of 15
in that case.

...13
......14
.........15
............16
...............17

Sum = 75.

Ans 17

75 makes more sense. Please check for any typos when posting questions. It may be unintentonal on our part so its always good to double check. Just a friendly suggestion...



Regards,
CR