Answer:
The group will need to take a minimum of 5 buses to carry all the people to the trip
Explanation:
Given:
Number of 7th grade students going on the trip = 178
Number of chaperones going on the trip = 20
Number of people each bus can hole = 42
To find the number of buses the group will have to take.
Solution:
Let minimum number of buses the group will have to take =

using unitary method:
If 1 bus can hold = 42 people
Then,
buses can hold =
people
Total number of people for the trip =

The total number of people that can go in
buses must be greater than or equal to 198 in order to carry all the people to the trip.
Thus we have the inequality:

Solving for

Dividing both sides by 42.

[As number of buses must be in whole number]
Thus, the group will need to take a minimum of 5 buses to carry all the people to the trip.