Question

10 increased by what percent is 30

Answer 1

10 increased by x%

$10+x\%\cdot 10=30\\\\ 10+0.01x \cdot 10=30\\\\ 0,1x=20\ |*10 \\\\x=200$

x% = 200%

Answer 2

It is a 200 percent increase because it increases by 20, which is 200% of or 2 times 10.