Question

A mustard seed has a mass of about 0.002. A glass jair contains about 4.3602 x 10 ^ 4 seeds. Which is a reasonable estimate of the mass of the mustard seeds in the jar?
a.(2 x 10 ^-3) x(4 x 10 ^4)= 8 x 10 ^7
b.(2 x 10 ^-3) x (4 x 10 ^4)=8 x 10 ^1
c. (2 x 10 ^-2) x ( 4 x 10 ^4)=8 x 10 ^6
d. (2 x 10 ^-2) x (4 x 10 ^4= 8 x 10^2

Answer 1

It would be B. because 0.002 x 40000 is 80. If you change 80 into a scientific notation it would be 8 x 10^1. Hope this helps! :) Let me know if you have any questions.

Answer 2

Answer:

B

Step-by-step explanation:

The mass of a single seed can be written as $0.002=2*10^{-3}$

There are total of $4.3602*10^{4}$ seeds in the jar

Total mass is the multiplication of these both numbers.

Since we want an estimate, we can use 4 instead of 4.3602 in the 2nd number.

The rule to multiply two numbers in scientific notation is:

$(a*10^{b})*(c*10^{d})=(a*c)*10^{b+d}$

So using this formula we multiply the 2 numbers and get answer as follows:

$(a*10^{b})*(c*10^{d})=(a*c)*10^{b+d}\\(2*10^{-3})*(4*10^{4})=(2*4)*10^{-3+4}\\=8*10^1$

Answer choice B is right.