Could you do 31 add 31 which would also be 31 multiplyed by 2
hope this helps
Average of 10 people = 65
65 × 10 = 650
average of 5 people = 35
35 × 5 = 175
650 + 175 = 825
825 ÷ 15 = 55
the average reading time for the entire book club each day is 55 minutes a day
19.05 if you have to round round to 19
