5 times the smaller of two numbers is subtracted from twice the larger, the result is 1. If the larger is increased by three times the smaller, the result is 61.

Tom had a total of $220 and he spent $35 on a basketball ticket . what percent of his money did he have left?

Me with this one question, and i'll upvote the brainliest answer

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.