Answer:
He spent
Fraction: 3/10
Weights: $ 210
He stayed
Fraction: 7/10
Weights: $ 490
Step-by-step explanation:
On the excursion Cristian spent 3/10 of what he had, therefore he still has:
1 - 3/10 = 7/10
Now, that 7/10 represents $ 490, to calculate what value 3/10 has, it would be:
(3/10) * 490 / (7/10) = $ 210
In total he had: 210 + 490 = $700
