Question

how much sand must be added to250lb of a cement mixture that is 22% sand to have a mixture that is 25% sand?

Answer 1

250(.22) + n(1.00) = (250+n)(.25)

Answer 2

okay hold on... let me see how you go about it

Answer 3

250(.22) + n = 250(.25) + n(.25)

n - n(.25) = 250(.25) - 250(.22)

n(1 -.25) = 250(.25 - .22)

n = 250 (.25 - .22) / (1 - .25)

Answer 4

gotta head to class .... good luck :)

Answer 5

igot10