Lesson 1, Problem 1

Dojo · Subject: Lesson 1, Problem 1 Fri Aug 15, 2008 5:37 pm

1) How many numbers are there from:
a) 2~20?
b) 7~16?
c) 4~13?

_________________
~Dojo

herefishyfishy1 · Subject: Re: Lesson 1, Problem 1 Sat Aug 16, 2008 6:36 am

Wait, can we post the answers here?

isabella2296 · Subject: Re: Lesson 1, Problem 1 Sat Aug 16, 2008 6:57 am

1) 20 - 2 + 1 = 19

2) 16 - 7 + 1 = 10

3) 13 - 4 + 1 = 10

Dojo · Subject: Re: Lesson 1, Problem 1 Sat Aug 16, 2008 11:59 am

@ fish yes
@ izzy sure thats one way but in my opinion theres a faster way.

_________________
~Dojo

AIME15 · Subject: Re: Lesson 1, Problem 1 Sat Aug 16, 2008 12:37 pm

Dojo wrote:

1) How many numbers are there from:
a) 2~20?
b) 7~16?
c) 4~13?

a) subtract one from the whole thing to get 1-19, so 19.
b) subtrac 6 from the whole lthing to get 1-10, so 10
c) subtract 3 from whole thing to get 1-10, so 10.