general Maths Puzzle

There is a staircase with 20 steps. A child runs up the steps, either 1 step or 2 steps with each stride. How many different ways can the stairs be climbed?

Read Solution (Total 4)

1+19C1+18C2 + 17C3 + ....+ 12C8+11C9 +1 ways
13 years agoHelpfull: Yes(8) No(1)

10946 ways. Fib(20) = 10926
12 years agoHelpfull: Yes(2) No(1)
89 ways are possible.
13 years agoHelpfull: Yes(0) No(2)
I think 89 is not correct.

There are much more number of ways .
13 years agoHelpfull: Yes(0) No(1)

general Other Question

Three people at a party discover that if you multiply the ages of any two of them, the product is the year in which the third person was born. In what year (since 1900) was the party held? By Using the digits 1 to 9, create two numbers which when multiplied together give you the highest number.
For example, 23456789 * 1 = 23456789, clearly there are higher products. What is the highest? And what are those two numbers?