Question

Helps Pls

Abbie decides to start doing crunches as part of her daily workout. She decides to do 10 crunches the first day and then increase the number 2 each day after that. Write an explicit formula for the number of crunches Abbie will do on day n.

a) f(n)=2n
b) f(n)=10n
c) f(n)=10+2n
d) f(n)=10+2(n-1)

Answer 1

It is given in the question that

Abbie decides to start doing crunches as part of her daily workout. She decides to do 10 crunches the first day and then increase the number 2 each day after that.

So the sequence of number of crunches are

`10,12,14,16,18,.....`

Here the first term, a , ia 10 and the constant difference,d, is 2.

To find the nth term, we use the formula of nth term of arithmetic series, which is

`a_(n) = a + (n-1)d`

Substituting the values of a and d, we will get

`a_(n) = 10+(n-1)2`

Therefore , correct option is d .