The average rate would be 2.9 because 20,600 divided by 7000 is 2.9
Answer:
14/5
Step-by-step explanation:
Let
be the common ratio between terms. Then
Now denote the
th partial sum of the series by
Multiply both sides by
, then subtract from the above to get
As
, you're left with
Nr of chocolates = c
nr of bags of 5 = a
nr of bags of 7 = b
50<c<70
c=5*a+2
c= 7*b-1 therefore b can be max 10 (if b=11 then c=76>70 can't do)
let's say b=10 then c=69 but in this case a=13.4 not integer (also can't do)
let's say b=9 then c=62 then a = 12 wich is ok
solution 1 c=62
let's also try for b=8 wich means c=55 and a=10.6, not integer, not ok again
and also for b=7 wich means c=48 but 48<50 so no go again and also for b<7 wich means c will grow smaller and smaller
so the only solution is c=62