Puzzle 5
What number comes next in this sequence:
302 · 202 · 102 · 002 · 991 · ?
Puzzle Copyright © Kevin Stone
workings
hint
answer
print
www.brainbashers.com
/puzzle/ziei
share
Hint
Try reversing the numbers.
Answer
891.
If we reverse each of the numbers we get:
203 · 202 · 201 · 200 · 199 · ?
Which is counting down from 203, and the next number is 198, which is 891 when reversed.
Puzzle 6
Alex likes soda very much. At the local convenience store, for every 5 empty soda bottles the reward is a full fresh bottle.
As part of a local recycling initiative, Alex collected 77 empty bottles.
How many bottles of soda could Alex drink in total?
Puzzle Copyright © Kevin Stone
workings
hint
answer
print
www.brainbashers.com
/puzzle/zyyp
share
Hint
The answer is not 15.
Answer
19 bottles.
Reasoning
From the initial 77 bottles, 75 bottles can be recycled for 15 new full bottles.
Once those are drunk, Alex will have 17 empty bottles (15 plus the 2 extra empty bottles).
From the 17 empty bottles, 15 bottles can be recycled for 3 new full bottles.
Once those are drunk, Alex will have 5 empty bottles (3 plus the 2 extra empty bottles), which can be recycled for one final full bottle.
Giving a total of 15 + 3 + 1 = 19.
Puzzle 7
At a recent visit to the reptile house at the local animal sanctuary, I counted a total of 27 heads and 70 feet.
I was counting snakes, lizards, and people and I know that there were exactly twice as many lizards as people.
How many snakes did I count?
Puzzle Copyright © Kevin Stone
workings
hint
answer
print
www.brainbashers.com
/puzzle/zlho
share
Hint
Snakes don't have legs.
Answer
6 snakes, along with 7 people and 14 lizards.
Reasoning
We know that for each person (2 legs) there were 2 lizards (4 legs each).
Which means for every person, we can count a total of 10 legs.
Snakes don't have legs, so the total of 70 legs must have been 7 people (and 14 lizards).
This is a total of 21 heads, so the remaining 6 heads were all snakes.
Double-Checking
7 people gives 7 heads and 14 feet.
14 lizards gives 14 heads and 56 feet.
6 snakes gives 6 heads and 0 feet.
For a total of 6 + 7 + 14 = 27 heads, and 0 + 14 + 56 = 70 feet.
