7 1.7 Puzzles for Homework
Exercise 1.7.1
There are four known solutions to the following math puzzle, in which you can move just one line to fix the equation. How many solutions can you find?
Exercise 1.7.2
Are the following statements true?
- Letters A, B, C and D do not appear anywhere in the spellings of 1 to 99
- Letter D appears for the first time in “hundred”
- Letters A, B and C do not appear anywhere in the spellings of 1 to 999
- Letter A appears for the first time in “thousand”
- Letters B and C do not appear anywhere in the spellings of 1 to 999,999,999
- Letter B appears for the first time in “billion”
- Letter C does not appear anywhere in any word used to count in English
