Ques 1.
Milk contains 10% water,what quantity of pure milk should be added to 20 litres of milk to reduce this to 4%?
Solution :
4/100 * (20+m)= 2
Ques 2.
A train starts from Jammu for Srinagar at 13:30 and reaches at 17:30 another train starts from Srinagar at 15:30 and reaches Jammu at 19:00 at what time both train meet?
Solution :
13.5 + (4*5.5)/(4+3.5) = 16:26
Ques 3.
The average age of class of 39 students is 15 years . If the age of the teacher be included , then the average increases by 3 months. Find the age of teacher ?
Solution :
15years*12 = 180months*39 = 7020months
183*40 = 7320months
7320-7020 = 300months/12 = 25years
Ques 4.
Tea worth Rs. 126 per kg and Rs. 135 per kg are mixed with a third variety of tea in the ratio 1 : 1 : 2. If the mixture is worth Rs. 153 per kg, what is the price of the third variety per kg ?
Solution :
4*153= 126+135+2x
X= 175.5
Ques 5.
When an article is sold for RS. 703 loss incurred is 25% less than the profit earned on selling it at 836 . what is the selling price of the article when it earns a profit of 20% ?
Solution :
836-X = 100/75 (X-703)
X = 760
==>760*120% = 912
Ques 6.
10 24 52 ? 220 444 892
Solution :
The given series is ×2 +4, ×2 +4, ...
==> 52*2+4= 108
Ques 7.
a,b,c are pipes attached to a cistern,A&b can fill it in 20min and 30min, while c can empty in 15min.if a,b and c kept open successively for 1 min each,how soon will the cistern be filled?
solution :
3 min = 1/60 tank fill
Let the number intervals of three minutes be x
x/60 +1/20 +1/30 = 1
x + 5 = 60
x = 55
Time needed to fill the tank completely is = 55*3 + 2 = 167
Ques 8.
Dinky is picked up by his father by car from school everyday and they reach home at 5.00 pm. One day, since school got over an hour earlier than usual, he started walking towards home at 3 kmph. He met his father on the way and they reached home 15 minutes earlier than their usual time. What is the speed of the car?
Solution :
He reaches 15 min early in home means he save 15min of his father time..15 min both way so 15/2=7.5 one way
But according question he should reached 1 hr earlier because school off 1 hr earlier so he spend tym in walkng =60-7.5=52.5
Distance=3*52.5=157.5
Father speed=157.5/7.5=21kmph
Ques 9.
The distance between two stations,Delhi and Amritsar, is 450 km. A trainstarts at 4 pm from Delhi and movestowards Amritsar at an average speedof 60 km/hr. Another train starts fromAmritsar at 3.20 pm and movestowards Delhi at an average speed of80 km/hr. How far from Delhi will thetwo trains meet and at what time?
Solution :
40/60 * 80 = 160/3
450- 160/3 = 1190/3
T = (1190/3) / 140 = 17/6
4pm + 17/6 = 6:50
Distance = 17/6*60=170km
Ques 10.
A dealer buys an article listed at Rs. 100 and gets successive discount of 10% and 20% . He spends 10% of the CP on transportation. At what price he should sell to earn a profit of 15%?
Solution :
10+20-(20*10)/100= 28%
==>100-28 = 72%
==>72+7.2=79.2
==>23/20*79.2=91.08
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