A letter lock consists of three rings each marked with six different letters. The number of distinct unsuccessful attempts to open the lock is at the most__________?
A. 216
B. 243
C. 215
D. 729
Related Questions on Permutations & Combinations Mcqs
In a class there are 20 boys and 25 girls. In how many ways can a boy and a girl be selected?
A. 400
B. 500
C. 600
D. 20
How many four digit even numbers can be formed using the digits {2, 3, 5, 1, 7, 9}
A. 60
B. 360
C. 120
D. 240