Answer:
90
Step-by-step explanation:
Answer:

Step-by-step explanation:
since its only 2/5 of 1 hour, two 2/5 equal 4/5 so we divide the 12 2/3 by 2 to find the 1/5 which is 6 1/3
÷2=


Answer: .
Step-by-step explanation:
Answer:
Li Jing's formula i.e.
is right.
Step-by-step explanation:
Considering the sequence

A geometric sequence has a constant ratio r and is defined by





So, the sequence is geometric.
as



so



Therefore, Li Jing's formula i.e.
is right.
Answer:
1045384620173418506891046 number of copies
Step-by-step explanation:
10464929103984753671930600 ×55215278300