Problem:
The value of (19,367)(.05)(487,000)(12,027,300)+(9,621,001)(487,000)​ is closest to
Answer Choices:
A. 10,000,000
B. 100,000,000
C. 1,000,000,000
D. 10,000,000,000
E. 100,000,000,000
Solution:
Rounding each number to one significant digit (highest place value) yields
(20,000)(.05)(500,000)(10,000,000)+(10,000,000)(500,000)​
which equals
1,000(500,000)(10,000,000+10,000,000)​
which equals
(500)(20,000,000)=10,000,000,000.
Answer: D​.
The problems on this page are the property of the MAA's American Mathematics Competitions