Teas costing $7 per pound are to be mixed with teas costing $4 per pound to make a 30-pound mixture. If the mixture is to sell for $6 per pound, how many pounds of each kind of tea should be used? A) 12 lb at $7/lb, 18 lb at $4/lb B) 15 lb at $7/lb, 15 lb at $4/lb C)20 lb at $7/lb, 10 lb at $4/lb

i did it myself and i got 4.2 (b) hope its right

step-by-step explanation:

idk

step-by-step explanation:

1,407.5 hours

step-by-step explanation:

we first convert all the time to hours and then sum them up.

there are 24 hours in 1 day, in 58 days, there are 24 x 58 = 1,392 hours.

there are 60 minutes in 1 hour, thus, 30 minutes will be equivalent to 30 / 60 = 0.5 hours.

therefore, the number of hours it will take mercury to complete a full rotation is 1,392 + 15 + 0.5 = 1,407.5 hours