please help me solve1-3

Note: Please show all your work and calculation setups to get full credit. Whenever an explanation or definition is required, full sentences must be used. The following may be used on this exam: 1cal=4.184J; specific heat of water =4.184J/gC; specific heat of ice =2.03J/gC; 1 mile (mi)=1609m;1 pound (lb)=453.59g;1ft=12 in.; 1 gallon (gal)=3.785L;1 in. =2.54cm.; heat of fusion of water=80. cal/g and its heat of vaporization is 540.cal/g;F=1.8C+32. You will need the values provided on the test. You will not get credit if you use any other sources. 1) ( 5pts ) Pure silver has a density of 10.5g/mL. A ring sold as pure silver has a mass of 45.0cg. When the ring is placed in a graduated cylinder containing water, the water level rises by 0.0280L. Determine whether the ring is pure silver or if the customer should see the Better Business Bureau. 2) (6 pts) At 35 cents/L, how much in dollars will it cost to fill an 87 -gallon tank with gasoline? (Hint: 1 gallon= 3.785L ). You must clearly show your calculation set-up. 3) (5 pts) The density of silver is 10.5g/mL. What mass of silver (in mg ) has a volume of 15ml