2 boys and 5 girls can finish a piece of work in 4 days. 4 boys and 4 girls can finish the same work in 3 days. If a girl is paid rs 750 each day, what may be the expenditure to complete the work?

Tomorrow is my test and I don't know how to solve this question. Someone please help!!!
Also that this question is from the chapter simultaneous equation.

how much is a boy paid?

boy does x jobs/day

boy does x jobs/day

girl does y jobs/day

(2 x + 5 y)4 = 1 job
(4 x + 4 y)3 = 1 job

8 x + 20 y = 1
12 x + 12y = 1

2 x + 5 y = 1/4
2 x + 2 y = 1/6
===============subtract
3 y = 3/12-2/12 = 1/12
y = 1/36
so a girl does (1/36) jobs /day
find x and you know jobs/day a boy does
If ONLY GIRLS work (we only know their pay)
it will cost 36*750

Thanks allot. that helped a lot . I hadn't even understood latter half of the question so this helped a lot

To solve this problem, we can set up a system of equations based on the given information.

Let's assume that the work done by one boy in one day is represented by "b" and the work done by one girl in one day is represented by "g". We need to find the total expenditure to complete the work.

From the first sentence, we know that 2 boys and 5 girls can finish the work in 4 days. Therefore, we can write the equation:
2b * 4 + 5g * 4 = Total Work

From the second sentence, we know that 4 boys and 4 girls can finish the work in 3 days. Therefore, we can write another equation:
4b * 3 + 4g * 3 = Total Work

Now, let's solve these equations to find the values of "b" and "g".

First, let's simplify the equations:
8b + 20g = Total Work
12b + 12g = Total Work

Since the total work in both equations is the same, we can equate them:
8b + 20g = 12b + 12g

By simplifying this equation, we get:
8g = 4b

Next, we can substitute the value of 4b from this equation into one of the original equations to solve for g or b. Let's choose the first equation:
8b + 20g = Total Work

Substituting 4b for 8g (from the previous equation), we get:
8b + 20(4b/8) = Total Work
8b + 10b = Total Work
18b = Total Work

Now we have the value of b.

To find g, we can substitute the value of b back into the equation 8g = 4b:
8g = 4 * (Total Work / 18)
g = (Total Work / 18) * (1/2)

Now that we have the values of b and g, we can calculate the total expenditure to complete the work.

The expenditure is given by the formula:
Expenditure = Number of Days * (2b * Rs 750 + 5g * Rs 750)

Substituting the values, we get:
Expenditure = 4 * (2b * Rs 750 + 5g * Rs 750)
Expenditure = 4 * (2 * Rs 750 * b + 5 * Rs 750 * g)
Expenditure = 4 * Rs 750 * (2b + 5g)

Now, substitute the values of b and g we found earlier to calculate the expenditure.

Note: Please make sure to check your calculations and units while solving the problem.