Answer:

Explanation:
GIVEN: At the first baseball game of the season, every
th person entering the ballpark received a coupon for a free hot dog. Every
th person received a coupon for a free soft drink.
TO FIND: number of the first person to enter the ballpark that received a coupon for a free hot dog and a coupon for a free soft drink.
SOLUTION:
As every
person receives coupon for free hot dog.
First person who receives coupon for free hot dog

similarly,
next persons who receives coupon for free hot dog


As every
person receives coupon for free soft drink.
First person who receives coupon for free hot dog

next persons who receives coupon for free hot dog

As
person is common in both.
therefore
person is the first person to enter ballpark that received a coupon for a free hot dog and a coupon for a free soft drink.