Question

A man makes a concrete mixture using cement sand and water in the ratio 1:3:6 respectively

A) if he uses 4 bags of cement how many bags of sand are needed

B) how many buckets of water are needed if he uses 10 bags of sand

C) how many bags of sand are needed if he uses 25 buckets of water

Answer 1

A) 12 bags of sand are needed

Explanation:

A) Your question is not complete because you didn’t mention the concrete volume. Let's assume you want to know the number of bags of cement required for 100 cft concrete considering 1:3:6 mix ratio. Lets begin!

Total volume of concrete= 100 cft

Mix Ratio= 1:3:6

Dry Volume of concrete= 1.5* Wet volume= 1.5*100cft= 150cft

Hence, Volume of cement required = 150*1/(1+3+6)= 15 cft

And, we know that one bag of cement contain 50kg or 1.25 cft Cement

Bags of Cement required = 15/1.25 = 12 Bags

Answer 2

Part A

The ratio of cement:sand:water is 1:3:6

This means we have 1 part cement, 3 parts sand, 6 parts water. These are the basic building blocks to form concrete and the smaller pieces must be in this ratio.

Focus on the first two values 1:3 since we're only worried about cement and sand for part A. We ignore the water element.

We have 4 bags of cement and x bags of sand that are in ratio 1:3

4:x = 1:3

4/x = 1/3

4*3 = x*1

12 = x

x = 12

Answer: 12 bags of sand

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Part B

This time we'll ignore the cement aspect. We only focus on the sand and water.

3:6 is the ratio of sand to water in that order.

x = number of buckets of water.

10 bags of sand to x buckets of water = 3:6

10:x = 3:6

10/x = 3/6

10*6 = x*3

60 = 3x

3x = 60

x = 60/3

x = 20

Answer: 20 buckets of water

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Part C

Like with part B, we'll ignore the cement.

x = number of bags of sand

x bags of sand to 25 buckets of water = 3:6

x:25 = 3/6

x/25 = 3/6

6x = 25*3

6x = 75

x = 75/6

x = 12.5

Answer: 12.5 bags of sand