Question

Mark studied a group of 30 whales. If each whale weighed approximately 3.8 * 10^5 pounds, find the total weight of all 30 whales. Express your answer in scientific notation.

Answer 1

Answer: The group weights 1.14x10^7 pounds

Explanation:

The group has 30 whales.

Each whale weights 3.8x10^5 pounds, then, 30 whales weight 30 times that amount:

Total weight = (30)*(3.8x10^5)

Remember that for the scientific notation we want only one digit before the decimal point.

Here, i will use that 30 = 3x10^1

(3x10^1)*(3.8x10^5) pounds = (3*3.8)x10^(5 + 1) pounds

(11.4)x10^6 pounds

and 11.4 = 1.14x10^1

(11.4)x10^6 pounds = 1.14x10^(1 + 6) pounds = 1.14x10^7 pounds

Answer 2

Answer: The total weight is
`(1.14)(10^(7))` pounds.

Explanation:

1. To solve this problem you need to multiply the number of whales by the weight. Based on the given information, the weight of each whale is approximately
`(3.8)(10^(5))` pounds, therefore:

`(30)[(3.8)(10^(5))]=11,400,000` pounds.

3. To express the result in scientific notation, you must move the decimal point to the right until you have a non-zero number on the left of the decimal point. Then, it is:

`(1.14)(10^(7))`