Question 978507: In a recent year, 6.5x10^8 metric tons of wheat were produced in the world. One metric ton is equivalent to 1000 kilograms. A grain of wheat weighs about .000008 kilograms. Find the number of grains of wheat that were produced in the world.
Sorry, i didn't know what category to place it in! But i think it has something to do with scientific notation. Thanks!! :D
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website! This is a unit conversion problem.
Given: 6.5 x 10^8 metric tons
Abbreviations for units:
KG = kilogram
MT = metric ton
Conversion factor: 1000 KG/1 MT
Multiply by the conversion factor to go from MT to KG
(6.5 x 10^8 MT) * (1000 KG/1 MT) = (6.5 x 10^8)*(1 x 10^3) = 6.5 x 10^11 KG
Notice how the MT units cancel
So, 6.5 x 10^8 MT = 6.5 x 10^11 KG
-------------------------------------------------------
Now use the fact that "A grain of wheat weighs about .000008 kilograms." to do another conversion
Conversion factor: 1 grain/0.000008 KG
Multiply by the conversion factor to go from KG to number of grains
(6.5 x 10^11 KG)*(1 grain/0.000008 KG)
(6.5 x 10^11 KG)*(1 grain/8*10^(-6) KG)
(6.5/8) x (10^11/10^(-6)) grains
(0.8125) x 10^(11-(-6)) grains
(0.8125) x 10^(11+6) grains
(8.125 x 10^(-1)) x 10^(17) grains
8.125 x 10^(-1+17) grains
8.125 x 10^(16) grains
The answer in scientific notation is 8.125 x 10^(16) grains of wheat
Expand that all out, to write into standard form, to get 81,250,000,000,000,000 grains (8125 followed by 13 zeros) of wheat
Note: In words, that large number above is eighty-one quadrillion, two hundred fifty trillion
|
|
|
