Question

Masonry There are 156 concrete blocks available to make a wall. The bottom three rows will all have the same number of blocks. The next six rows will each have two blocks fewer than the row below it. How many blocks are in each row?

Answer 1

There are 156 concrete blocks available to make a wall.

The bottom three rows will all have the same number of blocks.

The next six rows will each have two blocks fewer than the row below it.

Let there be x blocks in the first 3 rows.

As per the situation, the expression becomes:

`3x+x-2+x-4+x-6+x-8+x-10+x-12=156`

=>
`9x-42=156`

=>
`9x=156+42=198`

=>
`x=(198)/(9)`

x =22

So, there are 22 blocks in the first 3 rows.

And in each successive rows we have : 20,18,16,14,12 and 10

If we total all, we get 156.

`(22*3)+20+18+16+14+12+10`

`66+20+18+16+14+12+10=156`