Answer:
300
Step-by-step explanation:
Let x be the initial number. Initially, this number was 100%.
After an increase of 40%, it became 420 and 100% + 40% = 140% in percent.
So,
x - 100%
420 - 140%
Write a proportion:
[tex]\dfrac{x}{420}=\dfrac{100\%}{140\%}[/tex]
Cross multiply:
[tex]140\cdot x=420\cdot 100\\ \\140x=42,000\\ \\14x=4,200\\ \\x=\dfrac{4,200}{14}=\dfrac{600}{2}=300[/tex]
