Please help with these 2 problems, fill in the blank

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

Kayaks rent for $35 per day. which expression can you use to find the cost in dollars of renting 3 kayaks for a day?

Write the component forms of vectors u and v, shown in the graph, and find v − 2u. u= (< -3, -2> , < -3, -1> , < -2, -2> , < -2, -1> ) v= (< -5, 1> , -4, 0> , < 0, -4> , < 1, -5> ) v-2u= (< 5, 3> , < 0, 4> , < 4, 0> , < 5, -3>