Answer:
the average monthy attendance is 70 people attending the meal
Step-by-step explanation:
may is m and april is a
m=a+20
a=60
m=60+20
m=80
the amount of people who attended in may was 80
to find average, add all the sums then divide by the amount of them
(80+60+70)/3
210/3 (fyi :) 21/3=7)
70
the average monthly attendance is 70 attending the meal