Posted by **Anonymous** on Tuesday, September 13, 2011 at 8:40pm.

A child organizes animal blocks in rows on the ground. There are 64 animal blocks in the 5th row & 92 of those blocks in the 9th and last row. Suppose that the number of animal blocks frm row to row form an arithmetic sequence.

The number of animal blocks in the first row is....

I can’t seem to find a pattern, having a hard time solving this problem too.

Also How do I find the total number of blocks used in the arrangement?

The answer somehow is 36, and the total number of blocks is 576. I dont know how to get this.

Im probably supposed to use one of these formulas... Sn = n[2a +(n-1)d]/2

Sn = n(a +tn)/2. Still I dont get how to do it

- Math Block Problem -
**bobpursley**, Tuesday, September 13, 2011 at 8:48pm
the difference between the ninth and fifth is 28, so that is between 4 rows, so the differnce between each row is 28/4=7

start with 9th and go down:

92

85

78

71

64

57

50

43

36 first row.

Sum them: Sn= 9(2*36+8*7)/2=9*(72+56)/2=

Sn=9*64=576

- Math Block Problem -
**Anonymous**, Tuesday, September 13, 2011 at 8:52pm
Thanks so much. I was so confused :)

## Answer this Question

## Related Questions

- MATH - A child organizes animal blocks in rows on the ground. There are 64 ...
- Math Help - A child organizes animal blocks in rows on the ground. There are 64 ...
- MATH Word Problem - A child organizes animal blocks in rows on the ground. There...
- Arithmetic Sequence - A child organizes animal blocks in rows on the ground. ...
- math - In an extra-sensory-perception experiment, a blindfolded subject has two ...
- math - christi rides her bicycle 7 blocks south. 3 blocks east, 5 blocks north, ...
- Physics - A delivery truck travels 19 blocks south, 25 blocks east and 24 blocks...
- physics - A row of six 1 N wooden blocks is being pushed across a tabletop at a ...
- math - a jar contains 27 blue blocks 18 red blocks 12 orange blocks and 43 green...
- Physics - Three identical blocks, A, B, and C, are on a horizontal frictionless ...