time and work Model Questions & Answers, Practice Test for ssc cgl tier 1 2024

Answer: (c)

Let efficiency of B is x

Days are inversely proportional to efficiency.

According to question

⇒3x – x = 40

⇒2x = 40

∴ x = 20

Time taken by A = x days = 20 days

Time taken by B = 3x days = 3 × 20 = 60 days

Time taken by A and B together = ${20 × 60}/{80}$

= 15 days

Answer: (d)

Given that, ${T_1}/{T_2} = 2/1$

∴ ${\text"Area of first drum"}/{\text"Area of second drum"} = {πr_1^2}/{πr_2^2} = 4/1$

time taken will be inversely proportional to the area

then required time ratio = $1/4$ = 1 : 4

Answer: (b)

(A + B)'s 1 hour's work = $(1/12+1/15)=9/60=3/20$

(A + C)'s 1 hour's work = $(1/12+1/20)=8/60=2/15$

Part filled in 2 hrs = $(3/20+2/15)=17/60$

Part filled in 6 hrs = $(3×17/60)=17/20$

Remaining part = $(1-17/20)=3/20$

Now, it is the turn of A and B and $3/20$ part is filled by

A and B in 1 hour.

∴ Total time taken to fill the tank

= (6 + 1) hrs = 7 hrs.

Answer: (c)

Answer: (a)

1 man's 1 day's work = $1/108$

12 men's 6 day's work = $(1/9×6)=2/3$

Remaining work = $(1-2/3)=1/3$

18 men's 1 day's work = $(1/108×18)=1/6$

$1/6$work is done by them in 1 day.

∴ $1/3$ work is done by them in $6×1/3=$ 2 days