Answer:
£850
Explanation:
We can compute the left-over amount by comparing that to the amount spent.
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setup
Written as ratios, we have ...
spent : left-over = 3/8 : 1 -3/8 = 3/8 : 5/8 = 3 : 5
Writing this using fractions, we have ...
left-over / spent = 5 / 3
solution
Solving for left-over gives ...
left-over = spent × (5/3) = £510×5/3 = £850
Nate had £850 left over.
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Additional comment
Nate's money totaled £510 +850 = £1360.
The fraction spent is £510/£1360 = 3/8, as required.