1 man = 2 woman = 3 boys
? 1 man + 1 woman + 1 boy = (3 + 3/2 + 1) boys = 11/2 boys
Here M1 = 3 M2 = 11/2, D1 = 88 and D2 = ?
According to the formula
M1D1 = M2D2
? D2 = M1D1/M2
? Required number of days
= 3 x 2 x 88/11 = 3 x 2 x 8 = 48 days
Efficiency of A = 50% [100/2]
Efficiency of B = 37.5% [100/(8/3)]
Efficiency of C = 12.5% [100/8]
Combined efficiency of A,B and C = 100%
So, they complete the work in 1 hour.
(12 men + 16 boys) can do a work in 5 days.
(60 men + 80 boys) can do a work in 1 day.
(13 men + 24 boys) can do a work in 4 days.
(52 men + 96 boys) can do a work in 1 day.
? 60 men + 80 boys = 52 men + 96 boys
8 men = 16 boys and 1 man = 2 boys
Now, 12 men + 16 boys = (12 x 2 + 16) boys
= 40 boys can do the work in 5 days
? 5 men + 10 boys = [5 x 2 + 10] boys
= 20 boys will take
= (40 x 5)/20 = 10 days
Three day work or Ram, Rahim and Robert = 1/7 + 1/8 + 1/6
= (24 + 21 + 28)/168 = 73/168
Their six days work = (2 x 73)/168 = 146/168 = 73/84
Now, its Ram's turn to work on seventh day.
? 73/84 + 1/7 = 73 + 12/84 = 85/84 > 1
So, Ram will finish the work before the end of day.
Hence, Ram is working for the last day.
Combined efficiency of A and B = 1/72 ....(i)
Combined efficiency of B and C = 1/120 ....(ii)
Combined efficiency of A and C = 1/90 ....(iii)
On adding Eqs. (i), (ii) and (iii), we get
2(A + B + C) = 1/72 + 1/120 + 1/90 = (5 + 3 + 4)/360
= 12 / 360 = 1 / 30
? A + B + C = 1/60 .....(iv)
i.e Combined efficiency is 1/60 or we can say together A, B and C can complete the work in 60 days.
On subtracting Eq. (ii)from Eq. (iv), we get
Efficiency of A = Combined efficiency of A, B and C - Combined efficiency of B and C
= 1/60 - 1/120 = 1/120
Hence, A alone can do it in 120 days
In this question, A and B did the work for 35 days to complete it. A can complete the work in 60 days.
So, A did/A can + B did/B can = 1
? 35/60 + 35/x = 1
? x = 84 days
According to the formula,
Required time = ?ab
Where a = 25 and b = 49
? Require time = ?25 x 49 = 5 x 7
= 35 days
Time taken to complete the work by X =10 x 4 = 40 = 40 days
Time taken to complete the work by Y = (40 x 100)/40 = 100 days
Time taken to complete the work by Z = 13 x 3 = 39 days
Hence, Z will complete the work first.
(P + Q)'s 10 day's work= (1/30) x 10 = 1/3
Remaining work = (1 -1/3) = 2/3
2/3 work is done by P in 20 days.
? Whole work is done by P in 20 x (3/2) = 30 days
Here A = 60 days, B = 75 days, D = 30, T = ?
? Required time = (B - D) x [A/(A + B)]
= (75 - 30) x [60/(60 + 75)]
= (45 x 60)/135 = 20 days
? Required time = 20 days
Given, M1 = 20 D1 = 7, M2 = 20 + 8 = 28
and D2 = ?
Using formula, M1D1 = M2D2
? 20 x 7 = 28 x D2
? D2 = (20 x 7)/28 = 5 days
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