I like the 'question mark' at the end:
26 letters (English), 10 digits (0,1,...9)
26*26*10*10*10 = 676000
Now, this was for LLDDD (Letter Letter Digit Digit Digit)
It seems this is the order they want. Other wise, one should multiply by all the combinations in the order: LDLDD, DLLDD, etc ... (10 combinations), but again it seems they want this LLDDD
So 676000
Answer:
As a fraction, the answer is exactly 86/969
In decimal form, the answer is approximately 0.08875
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Work Shown:
The assumption is that no replacements are made for each selection.
5 red, 6 blue, 8 green
5+6+8 = 19 total
A = P(3 red) = (5/19)*(4/18)*(3/17) = 10/969
B = P(3 blue) = (6/19)*(5/18)*(4/17) = 20/969
C = P(3 green) = (8/19)*(7/18)*(6/17) = 56/969
D = P(3 all same color)
D = A+B+C
D = 10/969 + 20/969 + 56/969
D = (10+20+56)/969
D = 86/969
D = 0.08875
You just multiply the option amounts :) 4x2x7x3=168
<span>a/b = 3/5 ----- a = (3b)/5
a + b = 136 --- (3b)/5 + b = 136
3b + 5b = 680
8b = 680
b = 85
a = (3b)/5 = (3 * 85)/5 = 51
a = 85 and b = 51</span>
