Explanation

Given:

Time taken by A and B to complete the work = 12 days

Time taken by B and C to complete the work = 8 days

Time taken by C and A to complete the work = 6  days

Formulae used:

Time = Total work / Efficiency

Calculation:

Let us assume the total work is 1 unit.

⇒ A and B complete 1 unit work in 12 days → (A and B)'s 1 day's work = 1/12​

⇒ B and C complete 1 unit work in 8 days → (B and C)'s 1 day's work = 1/8​

⇒ A and C complete 1 unit work in 6 days → (A and C)'s 1 day's work = 1/6​

Adding everyone's 1 day's work:

$\Rightarrow 2(A+B+C)=(1/12+(1/8)+(1/6)$

⇒A+B+C=9/48​

= A, B, and C's 1 day's work = 9/48

⇒ B's 1 day's work = $(A+B+C)-(A+C)$

⇒ B's 1 day's work =(9/48)−(1/6) = 9-8 x/48 = 1/ 48 ​

​

⇒ B completes 1/48​ of the work in 1 day.

Therefore, B alone will take 48 days to complete the work.

Explanation

Given:

Time taken by 6 men to complete work= 10 days

Solution:

Time taken by 1 man = 6 x 10 = 6o hours

The time taken by 4 men to complete the work:

60/ 4 = 15 hours.

Explanation

Given:

• 16 machines finish the work in 4 days

• Now we want to know how many days will take 8 machines for the same work

Concept:

More machines → Less time
Fewer machines → More time
This is an inverse proportion relationship.

So,

$$text{Days} propto frac{1}{text{Machines}}$$ $$text{New Days} = 4 times frac{16}{8} = 4 times 2 = 8 text{ days}$$

Explanation

Total time = 1 hour = 60 minutes

Commercials duration = 20 * 30 seconds

= 600 seconds

= 10 minutes

Percentage of hour taken by commercials = (10/60) * 100

= 16.67%

Nearest percent = 17%

Explanation

First, let's find the work rate of 10 men:

10 men construct 75 km in 5 days, so:

Work rate = 75 km / 5 days = 15 km/day for 10 men

Now, let's find the work rate for 15 men:

Work rate for 15 men = (15/10) × 15 km/day = 22.5 km/day

Now, let's find the time needed for 15 men to construct 45 km:

Time = Distance / Work rate

= 45 km / 22.5 km/day

= 2 days

Explanation

Distance = Speed × Time

= 102 km/hr × 12 hours

= 1224 km

Now, let's find the time it takes to cover the same distance at 96 km/hr:

Time = Distance / Speed

= 1224 km / 96 km/hr

= 12.75 hours

To convert hours to minutes:

12.75 hours × 60 minutes/hour = 765 minutes

Explanation

Given:

• Speed of train = 120 km per hour

• Time = 8 hours

Formula

Distance = Speed × Time

Distance = 120 × 8

= 960 km

Last updated on 06-March-2026

Explanation

The car travels 30 km in the first hour and 32 km in the second hour, total distance = 30 + 32 = 62 km.

Total time = 2 hours, so average speed = 62 ÷ 2 = 31 km/h.

Explanation

Then, Ahmed's age after 15 years $=(x+15)$ years.
Ahmed age of 5 years back $=(x-5)$ years.
Given, $(x+15)=5(x-5)$
$x+15=5x-25$
$5x-x=15+25$
$4x=40$

Explanation

Total work = 16 men × 10 days = 160 man-days
Time for 8 men = $frac{160}{8}$ = 20 days