Discuss the below:
Q1 There are total 8 digits and we wants to choose 4 digit from 8 digits for locks. Since in the number lock, we may choose combinations of repeated numbers. Thus first digit can be chosen from 8 ways. Since other second, third and fourth digits can be chosen from 8 ways .
Q2 Since there are 4 Orchids we choose exactly three different orchid then total no. of ways i.e. first orchid can be chosen by 4 ways (due to different colors), similarly remaining orchids can be chosen by 3 and 2 respectively.
Q3 a. Two letter followed by a four-digit integer. There are 26 letters and 10 digits. since repetition is allowed then we may choose these two letters by 26 ways and 0 is a leading numbers thus first digit can be chosen by 10 ways and similarly others can be chosen by 10 ways respectively.
b. Two letter followed by a four-digit integer. There are 26 letters and 10 digits. since repetition is allowed then we may choose these these letters by 26 ways and 0 is leading numbers thus first digit can be chosen by 10 ways and similarly others can be chosen by 10 ways respectively.