Bob, Celia, Sam and Daniel gave money to buy their boss a retirement gift. Sam and Daniel each gave the same amount of money. Celia gave $12 more than Daniel. Bob gave half as much as Celia gave. If the four workers contributed a total of $81, how much did Celia give?

here's the equation: x+x+(x+12)+ 1/2(x+12) =81

combine like terms

(x+x+x+1/2x) + (12+6) = 81

simplify

7/2x +18=

subtract 18 from both sides.

7/2x=63

multiply by reciprocal (aka 2/7)

x=18

18+12=30 so celia gave 30.

Hope this helps!

water molecules will move from the side of higher water concentration to the side of lower concentration until both solutions are isotonic. at this point, equilibrium is reached. in an isotonic solution, the flow of water in and out of the cell is happening at the same rate.

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