Two consecutive numbers in the Virahanka sequence are 987 and 1597. Class 7

Two consecutive numbers in the Virahanka sequence are 987 and 1597. Class 7

Question 1.

Two consecutive numbers in the Virahanka sequence are 987 and 1597. What are the next 2 numbers in the sequence? What are the previous 2 numbers in the sequence? Class 7

Solution:

Next two numbers are (987 + 1597) = 2584 and (1597 + 2584) = 4181.

Previous two numbers in the sequence are (1597 - 987) = 610 and (987 - 610) = 377.

Question 2.

Angaan wants to climb an 8-step staircase. His playful rule is that he can take either 1 step or 2 steps at a time. For example, one of his paths is 1, 2, 2, 1, 2. In how many different ways can he reach the top? Class 7

Solution:

Different ways are as follows :

1, 1, 1, 1, 1, 1, 1, 1;

1, 1, 1, 1, 1, 1, 2; 1, 1, 1, 1,1, 2, 1;

1, 1, 1, 1, 2,1,1; 1,1,1, 2,1, 1,1;

1, 1, 2, 1, 1, 1, 1; 1, 2, 1, 1, 1, 1, 1;

2, 1, 1, 1, 1, 1, 1; 1, 1, 1, 1,2, 2;

1, 1, 1, 2, 2, 1; 1, 1, 1, 2, 1, 2;

1, 1, 2, 2, 1, 1; 1, 1, 2, 1,2, 1;

2, 2, 1, 1, 1, 1; 2, 1, 2, 1, 1, 1;

2, 1, 1, 2, 1, 1; 2, 1, 1, 1, 2, 1;

2, 1, 1, 1, 1, 2; 2, 2, 2, 1, 1;

2, 2, 1, 1, 2; 2, 2, 1, 2, 1;

2, 1, 2, 2, 1; 2, 1, 2, 1, 2;

2, 1, 1, 2, 2. (Twenty four ways)

Question 3.

What is the parity of the 20th term of the Virahanka sequence? Class 7

Solution:

even