Answer:
a.) The sum of the weights of the two in insects is 0.0031 grams. (0.0031 grams)
b.) The fly is 0.0013 grams heavier than the gnat. (0.0013 grams)
Step-by-step explanation:
2.2 * 10^-3 = 2.2 * 1/1000 which is 2.2/1000.
9 * 10^-4 = 9 * 1/10000 = 9/10000
To add 9/10000 to 2.2/1000 we have to find the common denominator, which will be 10000.
So we do:
2.2/1000 * 10/10 = 22/10000
9/10000 + 22/10000 = 31/10000 = 0.0031.
The sum of the weights of the two in insects is 0.0031 grams.
To find how much heavier the fly is than the gnat we do:
22/10000 - 9/10000 = 13/10000 = 0.0013
The fly is 0.0013 grams heavier than the gnat.