CTET Maths - Time and Work
- Option : B
- Explanation :
of work is completed.
Remaining work = 1-() = 
Remaining period = 46 - 33 = 13 days
Less work, less men(direct proportion)
Less days, more men(Indirect proportion)
More hours/day, less men(Indirect proportion)
work :
Days 13:33 :: 117:x
hrs/day 9:8
× 13 × 9 × x = ()33 × 8 × 117
x = (3 × 33 × 8 × 117) / (4 × 13 × 9)
= 198 men
So, additional men to be employed
= 198 - 117 = 81
- Option : A
- Explanation : Let L is length of train in km and x is speed of the cyclist, Then (i) 400L = 42 - x (ii) 720 L = 12 + x On adding, we get 1120 L = 84 ⇒ L = (84 x 1000)/1120 = 75m
- Option : B
- Explanation : 13/Speed upstream = 5 and
28/Speed downstream = 5
∴ Speed upstream = 13/5 km/hr
and Speed downstream = 28/5 km/hr.
- Option : D
- Explanation : in each case, train has to travel its own length, to pass each man.
If x km/hr is speed of the train, then
Length = Relative speed x Time
∴ 9x - 18 = 10x - 40
⇒ x = 22km/hr.
