Question

7 men and 7 boy can do a work in 2 days How long will
1 man and 1 boy will take to do the same work

Answer 1

Let time taken by 1 men per day= 1/x
let time taken by 1 boy per day = 1/y
according to question

2/x +5/y = 1/4
and also
4/x+ 4/y = 1/3

after solving 1st equation we get

let 1/x = p and 1/y = q
there fore 2p+5q = 1/4
8p+20q= 1 ..........(1)

2nd eq.

same with it

4p+4q =1/3

12p+12q = 1..........(2)

by substitution method
in 1st eq.
p=1-20q/8....(3)
put eq 3 in eq 2

12(1-20q/8)+4q =1

it gives

(12-240q+32q)=4

-208q = -8

q = 8/208

q= 1/16

put q = 1/16 in eq 3

p=(1-20×1/16)/8

then after solving it u will get value of p

then put value of p and q in 1/x and 1/y to get x and y

this taked lot of efforts hope you will understand
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and mark as brainliest

Answer 2

Answer:

14 days

Step-by-step explanation:

I DON'T NO . COZ I SAW THE ANSWER FROM K.C.NAG CLASS 8 BOOK FROM PAGE 141 EXERCISE 15 MATH NUMBER 34