IBPS RRB 2017 Prelim – Quants Test Day 9

Explanation
No of PIXEL mobiles remain unsold in year 2014 and 2015= 850000*20% +860500*31%= 170000+266755 =436755
No of LAVA mobiles remain unsold in year 2014 and 2015=650000*44% +794000*25% =484500

Difference =47745

Explanation-
total phone sold in all year by OPPO=
862000*88%+423000*55% +612000*75% +876000*80% +842000*35%=24,45,710

Average mobile sold all these years =489142

Explanation
Mobile phones sold in 2013 of MI=480000*72%=345600
Mobile phones unsold in 2016 of NOKIA= 850000*20%=170000

Difference=1,75600

Explanation
Mobile phones sold in 2015= 876000*80%+794000*75%= 700800+595500=1296300
Mobile phones sold in 2014= 6,12000*75% +6,50000*56%= 4,59,000+3,64,000=8,23,000

Percentage increase= ((1296300-823000)/823000))×100=57.51%

explanation
Total number of drink bottles = 6 + 3 + 4 = 13.
Let S be the sample space.
Then, n(S) = number of ways of taking 3 drink bottles out of 13.
Therefore, n(S) = 13C3=286
Let E be the event of taking 3 bottles of the same variety.
Then, E = event of taking (3 bottles out of 6) or (3 bottles out of 3) or (3 bottles out of 4)
n(E) = 6c3+ 3C3 +4C3=25
The probability of taking 3 bottles of the same variety = n(E)/n(S) = 25/286
Then, the probability of taking 3 bottles are not of the same variety = 1 – 25/286 = 261/286

Explanation-

25km/hr = 25 x 5/18 = 125/18 m/sec
and 30km/hr = 30 x 5/18 = 150/18 m/sec.
Let the length of the train be X meters and its speed by Y m/sec
Then the relative speed of the train and the bike with speed 125/18 m/sec is (Y – 125/18)
And the relative speed of the train and the bike with speed 150/18 m/sec is (Y – 150/18).
Relative distance covered is equal which is equal to length of train=

(Y-125/18) *18= (Y-150/18) *21

Y=50/3

Distance of train (50/3-125/18) *18 =175 m

Explanation
Initial speed of the cyclist = 7km/hr.
Distance covered in 1st 3 hours = 7 x 3 = 21 km.
After increasing, 1km/hr for every 3 hours period,
Distance covered in 2nd 3 hours period = 8 x 3 = 24 km.
Distance covered in 3rd 3 hours period = 9 x 3 = 27 km.
Distance covered in 4th 3 hours period = 10 x 3 = 30 km.

Total distance covered = 21 + 24 + 27 + 30 = 102 km.
Remaining km to cover = 113 – 102 = 11 km.

Speed in 5th 3 hours period = 11 km/hr.
Time to cover 13 km at 11km/hr = 11/11 hours = 1 hour.
Now, the total time taken by him for 113 km = (3 + 3 + 3 + 3 + 1) = 13 hours.

explanation
Let A’s investment be X
Then, B’s = X + 10,000 and C’s = X + 10,000 + 8,000
Now the total investment = X + X + 10,000 + X + 10,000 + 8,000 = 3X + 28,000
From the given data, 3X + 28000 = 1,00,000
3X = 72,000
then X = 24,000.
A: B: C = 24000: 34000: 42,000 = 12: 17: 21
Then c’s share = (21/50) x 70,000 = Rs. 29,400