**Sol : **In this kind of questions we find the work force required to complete the work in 1 day (or given unit of time) then we equate the work force to find the relationship between the efficiencies (or work rate) between the different workers.

Therefore 6B+8G = 6 days

6(6B+8G)= 1 day (inversely proportional)

36B+48G =1 ( by unitary method)

Again 14B+10G = 4days

56B+40G =1

so, here it is clear that either we employ 36B and 48G to finish the work in 1 day or 56B and 40G to finish the same job in 1 day. thus , we can say

36B+48G = 56B+40G

20B = 8G

G= 2.5B

Thus a Girl is 2.5 times as efficient as a boy.

Now, since 36B+48G = 1

36B+48 (2.5 B)=1

156B=1

i.e., to finish the job in 1 day 156 boys are required or the amount of work is 156 boys-days

Again 1G+1B=2.5B+1B=3.5B

Now, since 156 boys can finish the job in 1 day

so 1 boy can finish the job in 1 156 days

3.5 boys can finish the job in = days.

A) 17 days | B) 11 days |

C) 15 days | D) 16 days |

Explanation:

We know that Time is inversely proportional to Efficiency

Here given time ratio of P & P+Q as

P/P+Q = 150/100 = 3:2

Efficiency ratio of P & Q as

P:Q = 2:1 ....(1)

Given Efficiency ratio of Q & R as

Q:R = 3:1 ....(2)

From (1) & (2), we get

P:Q:R = 6:3:1

P alone can finish the work in

22.5(3+1)/6 = 15 days.

A) 8 | B) 6 |

C) 4 | D) 2 |

Explanation:

Total Water reqduired = 5000 × 150 lit

= 750,000 litres = 750 cu.m.

Volume of tank = 20 × 15 × 5 = 1500 Cu.m.

Number of days required =1500/750 = 2 days.

A) 8 days | B) 12 days |

C) 14 days | D) 10 days |

Explanation:

Ratio of efficiencies of Priya and Sai is

Sai : Priya = 160 : 100 = 8 : 5

Given Priya completes the work in 16 days

Let number of days Sai completes the work be 'd'

=> 5×16 = 8×d

d = 10 days.

Therefore, number of days Sai completes the work is 10 days.

A) 50 | B) 100 |

C) 70 | D) 35 |

Explanation:

Let the Efficiency of pavan be E(P)

Let the Efficiency of sravan be E(S)

Here Work W = LCM(25,20) = 100

Now, E(P+2S) = 100/25 = 4 ....(1)

E(2P+S) = 100/20 = 5 ....(2)

Hence, from (1) & (2) we get

E(S) = 1

=> Number of days Savan alone work to complete the work = 100/1 = 100 days.

A) 64 | B) 62 |

C) 58 | D) 56 |

Explanation:

Days remaining 124 – 64 = 60 days

Remaining work = 1 - 2/3 = 1/3

Let men required men for working remaining days be 'm'

So men required = (120 x 64)/2 = (m x 60)/1 => m = 64

Men discharge = 120 – 64 = 56 men.