High School

As a laboratory assistant, you must purchase supplies for the laboratory. If the laboratory uses, on average, about 75 grams of a certain compound every day, about how many kilograms of the compound will the laboratory use over 12 weeks?

A. 6.3
B. 8.4
C. 9.0
D. 63
E. 90

Answer :

To determine how many kilograms of the compound will be used over 12 weeks, we can follow these steps:

1. Calculate the total grams used per week:

Since the laboratory uses 75 grams of the compound every day and there are 7 days in a week, you can calculate the weekly usage as follows:

[tex]\[
75 \text{ grams/day} \times 7 \text{ days/week} = 525 \text{ grams/week}
\][/tex]

2. Calculate the total grams used over 12 weeks:

Multiply the weekly usage by the number of weeks to get the total usage over 12 weeks:

[tex]\[
525 \text{ grams/week} \times 12 \text{ weeks} = 6300 \text{ grams}
\][/tex]

3. Convert grams to kilograms:

Since 1 kilogram equals 1000 grams, you convert grams to kilograms by dividing by 1000:

[tex]\[
\frac{6300 \text{ grams}}{1000} = 6.3 \text{ kilograms}
\][/tex]

Therefore, the laboratory will use 6.3 kilograms of the compound over 12 weeks. The correct answer is A. 6.3.