Question

plz give answer and solution​

Answer 1

Answer:

When we go from the first digit to the last, the digit's value increases by 8 in six steps. Each step is one of -2, -1, +1, +2. The +8 can be done in 3 ways:

8=2×(+2)+4×(+1)

8=4×(+2)+(+1)+(−1)

8=5×(+2)+(−2)

In the first case, we just need to arrange +2's and the +1's in order. There are (62)=15 such arrangements.

In the second case, there are a total of 6!4!=30 ways to arrange the +2's, +1 and -1. But -1 can't appear last. There are 5 arrangements ending with -1. So there are 25 legitimate arrangements.

Now in the third case we again have 6 ways of placing the +2's and the -2. We just need to not count the one starting with -2 or ending with -2. This gives 4 arrangements.

Hence the final answer is 15+25+4=44