Answer: There were 6 guides on Sunday.
Explanation:
I suppose that this is a question about equivalent ratios:
It is said that the company had the same ratio of tourists to guides on Saturday and Sunday.
RATIO OF TOURISTS TO GUIDES:
SATURDAY: 120 : 18
SUNDAY: 40 : ?
Divide 120 by 40:
120/40 = 3
Divide 18 by 3:
18/3 = 6
Therefore:
SAT: 120 : 18
SUN: 40 : 6
Check it by multiplying both numbers in the ratio 40 : 6 by 3:
40 • 3 : 6 • 3
= 120 : 18
(You get the ratio from Saturday)
Hope this helps!