Question

The price of a watermelon at a fruit stand goes up 7 cents each month. The first month the stand was open, a watermelon cost $1.25.
What will the cost of a watermelon be in the 30th month?

A.) $ 1.55
B.) $ 3.28
C.) $ 3.35
D.) $ 21.55

Answer 1

Answer: Option 'B' is correct.

Step-by-step explanation:

Since we have given that

Cost of watermelon in the first month = $1.25

Every month it goes up by = 7 cents

so, it becomes an arithmetic progression:

1.25,1.32,1.39,......

So, here a = first term = 1.25

$d=a_2-a_1=0.07$

n = 30

So, our equation becomes,

$a_{30}=a+(n-1)d\\\\a_{30}=1.25+(30-1)0.07\\\\a_{30}=1.25+29\times 0.07\\\\a_{30}=\ 3.28$

Hence, cost of a watermelon would be $3.28 in the 30th month.

Therefore, Option 'B' is correct.