Let the unknown number be x. Since 60% of x is 279, we have: (60/100)x=279.
Here, 60/100 simplifies to 3/5 because the GCF 60 and 100 is 20, so the equation above can be rewritten: (3/5)x=279
Multiply both sides by 5: 3x=5·279 Divide both sides by3 to get x by itself,
we have: x=5(279/3)=5·93=465
CK: The difference between the quantity of 100% and 60% is 40%, that is: (40/100)x
Here,40/100 simplifies to 2/5, so 40% of x is: (40/100)x=2x/5
Substitutes x=465 for x, we have: 2x/5=2(465/5)=2·93=186, so 186+279=465 CKD.
The answer: the unknown number is 465.