Thirty six vehicles are parked in a parking lot in a single row. After the first car, there is one scooter, after second car there are three scooters and so on. Work out the number of scooters in the second half of the row ?

Options

A. 17
B. 15
C. 12
D. 28

Answer

B

Explanation

According to the pattern given in the question, there will be a total 8 cars and 28 scooters.
`therefore` Number of girls = `n/2[ 2a + (n - 1) d]`
`(because n=7, a = 1, d= 1) `
`= 7/2 [2 xx 1 +(7-1)10= 28`.
The arrangement is as shown below :
`{:("First half ",,"Second half"),("CSCSSCSSSCSSSSCSSS","/"," SSCSSSSSSCSSSSSSSC"):}`
So, the number of scooters in the second half of the row =15.