time and work Model Questions & Answers, Practice Test for ibps po prelims 2023

Answer: (b)

A's one day's work = $1/16$ th work

B's one day's work $1/12$ th work

Let the number of days B has worked alone = x days.

Then,

A's amount of work + B's amount of work = 1

⇒ $4(1/16)+(x+4)(1/12)=1$

⇒ $1/4+{x+4}/12=1 ⇒ x=3/4×12-4$

⇒ x = 5 days

Answer: (b)

Work done by both the taps in 5 min.

= $5 (1/{20} + 1/{25}) = (5 × 9/{100}) = 9/{20}$

Remaining part = $(1 - 9/{10}) = {11}/{20}$

Now, $1/{20}$ part is filled in 1 min.

So, ${11}/{20}$ part will be filled in 11 min.

Hence, the tank will be full in 11 min. more

Answer: (a)

A's 1 day's work = $1/{18}$ and B's 1 day's work = $1/9$.

∴ (A + B)'s 1 day's work = = $(1/{18} + 1/9) = 1/6.$

Alternate Method :-

As A is $1/2$ times efficient than B

Part of work A and B can finish in 1 day = $({1/2 + 1}/{1/2 × 18}) = 1/6$

Answer: (a)

Time taken by first man ${54}/8 = {27}/4$ h

∴ Time taken by second man

= $({27}/4 - 1/2 - {15}/{60})$h = 6 h

∴ speed of second man ${54}/6$ = 9km/h

Hence, ratio of their speeds = 8 : 9

Answer: (a)

50 men complete 0.4 work in 25 days.

Applying the work rule, $m_1×d_1×w_2=m_2×d_2×w_1$

we have,

$50×25×0.6=m_2×25×0.4$

or $m_2 = {50×25×0.6}/{25×0.4}$=75men

Number of additional men required = (75 – 50) = 25