David and Amrita had an equal number of marbles. After Amrita gave 50 marbles to David, he had 5 times as many marbles as her. Find the total number of marbles they had.

150

Step-by-step explanation:

Originally, they had the same number, so they both had x marbles each.

David: x

Amrita: x

Amrita gives 50 marbles to David. Now they have:

David: x + 50

Amrita: x - 50

"he had 5 times as many marbles as her"

x + 50 = 5(x - 50)

x + 50 = 5x - 250

-4x = -300

x = 75

Each had 75 marbles to start with.

75 + 75 = 150

The total is 150.

assuming you mean addition: addition and subtraction are reverse operations.

step-by-step explanation:

use an equation of ratios to determine the amount of gas needed to fill the tank.

    0.2             0.8

  =    

288.75             x

                                                              231 gal

so, 0.2x = (0.8)(288.75 gal), and x = = 1155 gal.

                                                                0.2

it would take 1155 gal. to fill the tank.

the cost would be

1155 gal         $3

* = $3465   (answer)

      1           1 gal

hope this you