Answer
The projected number of visitors for Spain is 70m.
The projected number of visitors for China is 140m.
Work Step by Step
Let $s$ be the projected number of visitors for Spain.
The projected number of visitors for China is 2s.
$s+2s=210$ $\longrightarrow$combine like terms
$3s=210$ $\longrightarrow$multiplication property
$3s\div3=210\div3$ $\longrightarrow$simplify
$s=70$
$2s=2\times70=140$
