Question

A sample of chemical weighs 1.006 kg. 80% of the sample is used in an experiment. What amount of chemical was used? Give the answer in grams.   [Round off to the nearest whole number if required]​

Answer 1

Given:

Weight of chemical sample= 1.006kg

The percentage used = 80%

To find:

The amount of chemical used

Solution:

Since 80% of chemical is used

so, 100-80 = 20% of chemical is left.

80% of 1.006 = 1.006 X 80/100

= 1.006 X 8/10

= 0.1006 X 8

= 0.8048 Kg

Since 1kg = 1000g

so  0.8048 Kg = 804.8g

Rounding off, we get the amount of chemical used = 805g