If you want to easily find the solution you can use your calculator.
Just divide 77 by 110 and see the result.
77/110 = 0.7 = 7/10 = 70/100 = 70%
100% - 70% = 30%
Explanation
110*x=77
x=77/110, but the answer is not a percent
So 77/110 = ?/100 => ?=77*100/110=70 => 70%
But since 70% does not represent a percentage decreasement, we need to subtract it from the 100%
100% - 70% = 30%
It is 28 i think been 3 year since i did this
The answer to this is x = 2
Y = yo + Vot - (gt^2)/2
y = 10 + 27t - 16.087t^2 [I used g = 32.174 ft/s^2]
You can find y with the quadratic formula or probe with the different times given.
I tried with t = 2 s and found
y = 10 + 27(2) - 16.087 (4) = 10 + 54 - 64.348 = -0.348
Then that is the answer, t = 2s.