We can view this problem as one of depreciation.
You are comparing 60,000 now to 10,000 that depreciates at 10% each year over the next 10 years.
We know the value of $60,000 in hand (it's just $60,000, naturally), so now we need to compare it to the $10,000 each year for the next 10 years.
At year 1:
P1 = 10,000
At year 2:
P2 = P1 + 10,000 * (0.90) (the 0.90 is the 10% loss from 100%)
At year 3:
P3 = P2 + 10,000 * (0.90)^2 (the 0.90^2 is a 10% loss from 100% compounded twice)
and so on and so forth. We need to add all of these terms to see if they exceed $60,000
Written out, we have
PT = 10,000 + 10,000 * (0.90) + 10,000 * (0.90)^2 + ... + 10,000 * (0.90)^9
or
PT = 10,000 * (1 + 0.9 + 0.9^2 + 0.9^3 + ... 0.9^9)
What we have in this case is a finite summation of powers, such that
a * sigma (i = 1, n) for r(i-1) = a * (1 - rn) / (1 - r)
where a = 10,000, r = 0.9 and n = 10
10,000 * (1 - 0.9^(10)) / (1 - 0.9) = 10,000 * (1 - 0.34) / (0.1) = 65,140
So our expected gain from the 10 year plan is $65,140, which exceeds the offering of $60,000.
You would decline the offer.