time and work Model Questions & Answers, Practice Test for ibps rrb clerk asst multipurpose prelims 2024

Answer: (d)

Part of the tank filled by the three pipes working simultaneously in one hour is = $1/5 + 1/6 - 1/{12} = {17}/60$

i.e. it takes ${60}/{17}$ hours to fill up the tank completely.

Now, $1/2$ of the tank is filled with all the pipes open, simultaneously together in ${60}/{17} × 1/2 = 1{13}/{17}$hours

Answer: (d)

Relative speed = (40 – 20) km/h

= $(20 × 5/{18})$ m/sec = $({50}/9)$ m/sec.

Length of faster train = $({50}/9 × 5)m = {250}/9 m = 27 {7/9}$m.

Answer: (c)

$m_1 × d_1 × t_1 = m_2 × d_2 × t_2$

24 × 10 × 8 = $m_2$ × 6 × 10

⇒ $m_2 = {24 × 10 × 8}/{6 × 10}$ = 32 men

Answer: (d)

Let A and B complete the work in x and y days, then,

$1/x + 1/y = 1/5$ ...(i)

and, $2/x + 1/{3y} = 1/3$ ...(ii)

From equation (i) and (ii), we have

$1/{3x} - 2/x = 1/{15} - 1/3⇒{1 - 6}/{3x} = {1 - 5}/{15} ; x = {25}/4 = 6 1/4$ = days

Answer: (d)

Let C be the time taken by the car and W by walking along one way.

Now, C + W = 6 hr 45 min.

Multiplying both sides by 2,

2C + 2W = 13 hr 30 min.

2W = 13 hr 30 min – 2 C ...(i)

Now, 2C = 6 hr 45 min – 2 = 4 hr 45 min ...(ii)

Putting value of 2C in (1),

2W = 13 hr 30 min – 4 hr 45 min = 8 hr 45 min