8 men 12 boys can complete work in 5 days and 6 men and 8 boys can complete work in 7 days find time taken by 1 man alone or that taken by 1 boy alone
Answers
Answer:
A car driver is traveling at a speed of 10m/s .
e.g., initial velocity , u = 10m/s
He applied break and brings to the car to rest in 20s.
so, time taken to stop the car = 20s
we have to find retardation.
final velocity of car , v = 0
use formula, v = u + at
0 = 10 + a20
a = -1/2 m/s² [hereative sign shows retardation ]
Step-by-step explanation:
Answer:
280 days
Step-by-step explanation:
Let the time taken by man be x days
time taken by boys be y days
work done by 1 man in one day=1/x
work done by 1 boy in one day=1/y
8/x+12/y = 1/10............eq 1
6/x+ 8/y = 1/14..........eq2
Let u=1/x & v=1/y
8u+ 12y=1/10.........eq3
6u+8v= 1/14...........eq4
Multiplying eq3 by 2 & eq4 by 3
16u+ 24y=2/10.........eq5
18u+24v= 3/14.........eq6
subtract eq 5 & 6
-2u= -3/14+2/10
-2u = (-3×10 +2×14)/140
-2u=( -30+28)/140
-2u=-2/140
u=1/140
put this value in eq 5
16u+ 24y=2/10
16×1/140 +24y =1/5
4/35+24y= 1/5
24y= 1/5-4/35
24y= (1×7 -4)/35
24y = (7-4)/35
24y= 3/35
y= 3/35×24
y= 1/280
u=1/x
1/140 = 1/x
x=140
v=1/y
1/280 = 1/y
y=280
A man complete the work in 140 days
A boy can complete the work in 280 days