Five friends agree to save money for a graduation road trip. they decide that each of them will put $0.25 in the fund on the first day of may, $0.50 on the second day, $0.75 on the third day, and so on. at the end of may, there will be $ in their fund. (hint: there are 31 days in may.)
** explain!

By may 31st there Will be $620 on their fund.

Step-by-step explanation:

Fund of the first day = $0.25 *5= $1.25

Fund of second day = $0.50*5= $2.5

Fund of third day = $0.75*5= $3.75

A Close observation shows there's an increase in amount to be saved by $0.25 and the total amount saved by 5 of them by $1.25.

So in the next 28 days... what will be there total.

Total = n/2(2a(n-1)d)

But where n= 31

a = 1.25

d = 1.25

Total = 31/2((2*1.25)+(31-1)1.25)

Total = 15.5(2.5+37.5)

Total= 15.5(40)

Total= 620

step-by-step :