Question

everyday luis buys 5 more baseball cards to add to his collection . if he has 25 baseball cards before making any purchases , how many will he have on day 20

Answer 1

Equation: Y=5x+25
X= 20days
Y=5(20)+25
Y=100+25
Y=125
Answer is 125cards

Answer 2

On the 20th day he will have 125 baseball cards.

Explanation:

We are given a statement that:

Everyday luis buys 5 more baseball cards to add to his collection . if he has 25 baseball cards before making any purchases.

We are asked to find how many will he have on day 20?

Let
`P_n` denotes the number of baseballs cards on nth day.

on the first day he will have:

`P_1=25+5`

on second day he has:

`P_2=P_1+5=25+5* 2`

On third day he will have:

`P_3=P_2+5=25+5* 3`

and so on on the nth day he will have:

`P_n=25+5* n`

We are asked to find the number of baseball cards on 20th day.

i.e. n=20

`P_(20)=25+5* 20\\\\P_(20)=25+100\\\\P_(20)=125`

Hence, on the 20th day he will have 125 baseball cards.