im very confursed on these two can you please show steps and explain

A house is valued at $350.000 and assessed for 60 percent of its value. If the tax bill is $6,300, what is the rate per $100? $3.00 $2.90 $3.50 53.95 D Question 7 5 pts How much would a sidewalk cost that is 3 wide. 50' long and 3" thick if the concrete is $134.50 per cubic yard and labor costs are $2.44 per square foot? 5224157 555281 5366.00 552.667 67