Question

Time taken by 3 Girl and 2 Boys to complete a work is 4 daysthe work done 5 girl is 7 days more than work done by 4 boys. The number of days in
which work is completed by a boy and girl working together is? ​

Answer 1

Step-by-step explanation:

B → Boy

G → Girl

According to ques,

3B = 4G (work done by 3 boys equals work done by 4 girls)

i.e. 1B = (4/3)G

Now we have to find work done by 7 boys and 5 girls together

i.e. 7B + 5G = 7*(4/3)G + 5G = (43/3)G

Time taken by 4G to complete the work = 43 days

So, time taken by 1G to complete the work = 43*4 days

[No. of people working is inversely proportional to no. of days, i.e. more the no. of people, less the time it will take to complete the job and vice versa.]

Therefore, time taken by (43/3)G to complete the work = (43*4)/(43/3) = 12 days

So, it will take 12 days to complete the work if 7 boys and 5 girls work together.

Answer 2

Answer:

Given :- Time taken by 3 Girl and 2 Boys to complete a work is 4 days . The work done by 5 girl is 7 days more than work done by 4 boys.  

To Find :- The number of days in which work is completed by a boy and girl working together is ?  

Answer :-  

Let us assume that,  

Efficiency of a girl = G unit/day .

Efficiency of a boy = B unit/day .

so,  

→ Total work = 4 * (3G + 2B) units .  

now,  

→ 5G completes the total work in = {(12G + 8B)/5G} days .  

and,  

→ 4B completes the total work in = {(12G + 8B)/4B} days .  

A/q,  

→ {(12G + 8B)/5G} - {(12G + 8B)/4B} = 7  

→ (48GB + 32B² - 60G² + 40GB)/20GB = 7  

→ 32B² - 60G² + 88GB = 140GB  

→ 4(8B² - 15G²) = 140GB - 88GB  

→ 8B² - 15G² = 13 .  

given data is incorrect to solve the problem .

Step-by-step explanation: