Six contestants must sit in a row at a contest. What number sentence shows the number of possible orders the contestants can sit in?

Question

Answers given include:

a. 6x6

b. 6+6

c. 5+4+3+2+1

d. 6+5+4+3+2+1

This is on a fourth grade math quiz. Order does matter! What strategy should the kids be using? Keep in mind their age. Thanks

Answer 1

None of the above

correct answer is 6! = 6x5x4x3x2x1= 720

it's possible 4th coice was miscopied with a + sign where it was intended to be x

try picking a few possibilities, call them persons A through F

so

ABCDEF is one, then keep going for awhile

ABCDFE

ABCEDF

ABCEFD

ABDCEF

ABDECF

ABDEFC

ABDFCE

ABDFEC

ABDECF

ABDFCE

ABDFEC

that's 12 just for those starting with ABD...

so much more than 12. that eliminates

2nd choice

then do this again for ABE... and ABF...

eventually you eliminate the smallest choices, 2nd, 3rd and 4th

leaving 1st choice as the "best" answer, even if it's wrong.

that's a common test instruction, picke the "best" answer, the one closest to the real answer, even if all the choices are wrong.