Question

The total use of electricity in the United States was 0.4 trillion kilowatt-hours in 1950 and about 2.8 trillion kilowatt-hours in 1990. How many times more electricity was there in 1999 than 1950? Use scientific notation

Answer 1

Answer: 7

Step-by-step explanation:

Scientific notation is a method that is used in very large numbers or when we've very small numbers. The number given will be multiplied by its power of 10. In this case,

2.8 trillion = 2,800,000,000,000

= 2.8 × 10^12

0.4 trillion = 400,000,000,000

= 4 × 10^11

Therefore, the times more electricity was there in 1999 than 1950 will be:

= (2.8 × 10^12) / (4 × × 10^11)

= (2.8/4) / (10^12 - 11)

= 0.7 × 10

= 7 times

There were 7 times more electricity that was there in 1999 than 1950.