Wa country health service Interview Questions, Process, and Tips

C. 96

Ramji sir

4.5

21 days

Total number of pairs is NC2^{N}C_2NC2​. Number of pairs standing next to each other = N. Therefore, number of pairs in question = NC2^{N}C_2NC2​ – N = 28/2 = 14. If N = 7,
7C2​ – 7 = 21 – 7 = 14….
N =7

X filling rate is 1/18 or 4/72 per hour

Y filling rate is 1/24 or 3/72 per hour

Combined as a pair it’s 7/72 in a complete 2 hour alternating sequence

72+ 7/72 =10 sequences = 70/72 on 20 hours, The outstanding balance is just 2/72

So at 20.5 hours with X turn filling is 100% complete with 72/72

Answer: It will take 20.5 hours to completely fill this tank.

Analysis of measured filling process, from X = 42/72 share & from Y = 30/72 share

0

12%

8/15 left.

1/15 * 4 + 1/20 * 4 = 7/15
1 – 7/15 = 8/15

A’s speed=6 mph ,B’s speed=8 mph
Let, after x hrs, they will meet.
so, the distance traveled by A in x hrs should be the same as the distance traveled by B in (x-1/2)hrs [as B started the journey after 30 min of A]
Thus, 6x=8(x-1/2)[as distance=speed*time]
=>8x-6x=4
=>2x=4
=>x=2
after 2 hrs they will meet so time=(9+2)=11.00 a.m

C

(b) 16.66%

Earlier for ₹x we could purchase y gm of sugar.
Now we pay ₹1.2x for y gm of sugar

(As there was an increase in price so, x + 20%x = 1.2x)

At current rates for ₹x you can purchase y/1.2 gm of sugar

So the reduced consumption is y-(y/1.2)

Percentage change = (reduced consumption/ original consumption ) *100

That is (0.2/1.2) *100 = 16.66% (approx)