To get the answer we can use proportion. We know that 350 its 100% and 378 its 100% + taxes.
350% ------------ 100
378% ------------ x
cross multiply now
350*x=378*100
350x=37800 /:350
x=108
Now we see that taxes its 8%, because final price its 100% + taxes = 108%
Basically 3 feet are in a yard and so you have to multiply X amount of yards by 3 to get feet and in this case you will get 120 as your Answer!<span />
We can solve this using the formula nth term = a+(n-1)d
so the 10th term will be 87
75th term will be 132
and nth will be 9n-3