Frozen Vegetables Recipes

Zadanie nr14

Broken calculator does not display the number 1 For example, if you type the number 3131, it shows the number 33 without any spaces between numbers. Michael wrote on this a number of six-digit calculator calculator and the display appears the number 2007. For how many numbers could happen?
A) 12
B) 13
C) 14
D) 15
E) 16 Solution

tasks:

need to add two number ones in 2007. Depending on where it is written from left to first number one, do a head count if it is possible to write the second jedynki.Pierwsza number one is:
* before 2007, we have 5 possible
* before 007, we have four possibilities,
* before 2007, we have 3 opportunities
* before 7, we have two possibilities,
* at the end, we have an opportunity. So

in total we have 1 +2 +3 +4 +5 = 15 possibilities.