Ques 1.
If I had walked 1 km/hr faster, I would have taken 10 minutes less to walk 2 km. Find the speed of my walking ?
Solution :
2/x - 2/x+1 =10/60
==> X = 3 kmph
Ques 2.
In a tank water is falling with same rate. Before 5 minute water was 91 liter and after 11 minute water was 139 liter. What is the value of water currently in tank?
Solution :
139-91=48/16=3 lit/min
==> 91+3(5)= 106
Ques 3.
The avg of 11 players of a cricket team is decreased by 2 months when two of them replaced by 17years and 20 years by 2 reserved players .find avg age of reserved players?
Solution :
11*2= 22mnths
37*12-22=422
422/2=211/12= 17yrs 7 mnths
Ques 4.
The average score of a cricketer for ten matches is 38.9 runs. If the average for the first six matches is 42, then find the average for the last four matches ?
Average for 10 matches = 38.9
Average for first six matches = 42
Average of last four matches = ?
Total sum of last 4 matches = (10 * 38.9) - (6 * 42)
= 389 - 252
Average = 137 / 4
Ques 5.
Monish is on tour and he has Rs 360 for his expenses. If he exceeds his tour by 4 days he must cut down daily expenses by Rs 3. Find the number of days of Monish′s tour program ?
Solution :
Let Monish under takes a tour of x days.
Then, expenses for each day = 360x
360 / (x + 4) = (360 / x) - 3
360 / (x + 4) = (360 - 3x ) / x
360x = (x + 4) (360 - 3x )
360x = 360x - 3x2 + 1440 - 12x
3x2 + 12x - 1440 = 0
3 (x2 + 4x - 480) = 0
x2 + 4x - 480 = 0
(x - 20) (x + 24) = 0
x=20 and - 24
x = 20 days
Ques 6.
A tank is connected to both inlet and outlet pipes . Individually an inlet pipe can fill the tank in 7 hrs and outlet pipe can empty it in 5 hrs.If all pipes are kept open it takes 7 hrs to empty a completely filled in tank.If total no of pipes are 11 how many of these are inlet pipes ?
Solution :
Let Number of inlet pipes X
(11-x)/5 -x/7=1/7
==> X= 6
Ques 7.
Aswin can cover a distance in 1hr 24 min by covering 2 / 3 of the distance at 4 kmph and the rest at 5 kmph. Find the total distance ?
Let total distance be D.
Distance travelled at 4 kmph speed = (2 / 3) of D
Distance travelled at 5 kmph speed = (1 - (2 / 3))D
= (1 / 3) D
Total time =1 hr 24 min
= (60 + 24) min
= 84 / 60 hr
= 7 / 5 hr
Time = Distance / Speed
7 / 5 ={ ((2 / 3) D) / 4 } +{ ((1 / 3) D) / 5 }
7 / 5 = 14D / 60
60 (7 / 5) = 14D
D = 84 / 14
Ques 8.
Speed of a boat in standing water is 14 kmph and the speed of the stream is 1.2 kmph. A man rows to a place at a distance of 4864 km and comes back to the starting point. Find the total time taken by him ?
Solution :
Speed downstream = (14 + 1.2)
= 15.2 kmph
Speed upstream = (14 - 1.2)
= 12.8 kmph
Total time taken = (4864 / 15.2) + (4864 / 12.8)
= 320 + 380
Ques 9.
A trader buys goods at 20% discount on marked price.If he wants to make a profit of 25% after allowing a discount of 20% by what per cent should his marked price be greater than the original marked price ?
Solution :
marked price -100
Selling Price -100*80/100=80
80*125/100=100
New Marked price=100*100/80=125
Difference = 125-100=25
Ques 10.
50 g of an alloy of gold and silver contains 80% gold (by weight). The quantity of gold, that is to be mixed up with this alloy, so that it may contain 95% gold, is
Solution :
5%------10
100%-----200
==>200-50=150
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