Saudi Arabia has proven oil reserves of

2.63  1011 barrels. Kuwait has proven
oil reserves of 9.78  1010 barrels.
Canada has proven oil reserves of
1.789  1011 barrels. What are the
combined proven oil reserves of the
three countries?

1 answer

2.63*10^11
0.978*10^11
1.789*10^11
--------------
5.397*10^11