The units digit of a three-digit number is 6. What is the probability that the number is divisible by 6? Express your answer as a common fraction.
Number of 3 digit integers = 999-100 +1 = 900
900/6 = 150 of them are divisible by 6
9 x 10 = 90 of them end in 6
every third one is divisible by 6 so 30 30/90 = 1/3 of the three digit numbers that end in 6 (given) are divisible by 6
There are: 126 156 186 216 246 276 306 336 366 396 426 456 486 516 546 576 606 636 666 696 726 756 786 816 Total = 24
You have: 999 - 100 + 1 =900 - 3-digit numbers
Probability =24 / 900 = 2 / 75
To be divisible by 6, the fist two integers must be divisible by 3......so...we can solve this for n
126 + 30 * (n) = 999
30 * (n) = 873 divide both sides by 30
(n) = 29.1
Take the ceiling of 29.1 = 30
So....30 three-digit integers ending in "6" are divisible by 6
And we have 999 -100 + 1 = 900 three-digit integers
So....the probability is 30 / 900 = 1 / 30
See EP's answer below....!!!!
Number of 3 digit integers = 999-100 +1 = 900
900/6 = 150 of them are divisible by 6
9 x 10 = 90 of them end in 6
every third one is divisible by 6 so 30 30/90 = 1/3 of the three digit numbers that end in 6 (given) are divisible by 6