Amina bibi has prepared masonry mixture with sand and cement in a ratio of 7:1. But after the brick-work , it is seen that 72 kg of mixture remains. She has added more cement with this mixture and the ratio of measurement of sand to cement becomes 6:1
Find out the total quantity of cement she has mixed.
Pls answer fast with step by step explanation.
Pls don't spam or I will have to report your answer.
Thank you!
Answers
Step-by-step explanation:
think you're asking how much cement was added to 72 kilograms of the mixture to make the ratio of sand to cement = 6/1 rather than 7/1.
the ratio starts at 7 to 1.
that means 7 parts out of 8 is sand and 1 part out of 8 is cement.
the total number of parts is 8.
72 / 8 = 9
each part is worth 9 kilograms.
7 * 9 = 63 kilograms of sand.
1 * 9 = 9 kilograms of cement.
72 kilograms of mix is equal to 63 kilograms of sand and 9 kilograms.
you add x kilograms of cement to the mixture.
you now have 63 kilograms of sand and 9 + x kilograms of cement.
the ratio of sand to cement is now 6 to 1 rather than 7 to 1.
63 / (9 + x) = 6 / 1
multiply both sides of this equation by (9 + x) to get 63 = 6 * (9 + x) / 1
simplify to get 63 = 54 + 6x
subtract 54 from both sides to get 63 - 54 = 6x
combine like terms to get 9 = 6x
divide both sides by 6 to get 9 / 6 = x which makes x = 1.5 kilograms.
the amount of cement that is added to the mixture is 1.5 kilograms.
you now have 63 kilograms of sand and 9 + 1.5 = 10.5 kilograms of cement.
the new mixture contains 63 kilograms of sand and 10.5 kilograms of cement which is equal to a total mixture of 73.5 kilograms.
the sane to cement ratio is now 63 / 10.5 = 6 / 1.
.
So, we have 72 kg of the mixture containing sand and cement in the ratio 7:1.
It means that there are 7+1 = 8 parts of the equal mass; each mass is = 9 kilograms.
So, there are 7*9 = 63 kilograms of the sand and 9 kilograms of the cement in the original mixture.
We want to add "x" kilograms of the cement to get the ratio sand to cement 6:1.
63%2F%289%2Bx%29 = 6%2F1 ====>
63 = (9+x)*6
63 = 54 + 6x
x = %2863-54%29%2F6 = 9%2F6 = 1.5 kilograms of cement to add. ANSWER