Ques 1.
Two women A and B , working separately can mow a field in 8 and 12 hours respectively. If they work for an hour alternately, A beginning at 9 am, when will the mowing be finished?
Solution :
L.C.M of 8 and 12 = 24
total work = 24 units
A efficiency = 24/8=3
B efficiency = 24/12 = 2
total efficiency = 3+2=5
working alternatively = 24/5 = 4 remaining 4 Units
next A turn its finish 3 units work in 1 hour , B finish 1 unit in 1/2 hour
Total hours = (4*2)+1+1/2 = 9 1/2 hour
Time = 9am + 9 1/2 = 6:30pm
Ques 2.
A man purchased 150 pens at the rate of rs120per pen. He sold 50 pens at a gain of 10%. The % gain at which he must sell the remaining pens so as to gain 15% on the whole outlay is ?
Solution :
50 is 1/3 of 150
(1/3)*10 + (2/3)*x =15
Ques 3.
Siva goes to a supermarket and bought things worth rupees 60, out of which 40 paise went on sales tax. If the tax rate is 10 percent, then what was the cost of tax free items?
Solution :
0.4 -----10%
X ------ 100%
X=4
==>60-(4+0.4) = 55.6
Ques 4.
1 7 49 343 ?
Solution :
1×7=7
7×7=49
49×7=343
343×7=2401
Ques 5.
rakesh gave 1∕4th of 40% of her monthly salary to Park Out of the amount Pari received from rakesh.she gave 30% to the maid and the remaining Rs 2.520 Pari Kept with herself. What was rakesh’s monthly salary ?
Solution:
1/4×40%=10% to pari
10%×30%=3% to maid
7% remain------2520
100%-----------36000
monthly salary =36,000
Ques 6.
The price of an article is first increased by 20% and later on the price were decreased by 25% due to reduction in sales. Find the net percentage change in final price of Article.
Solution :
=20-25-(500/100)=-10
10% loss
Ques 7.
A & B finish a work in such a way, if A work for 2days and left then B will finish remaining work in 9 days. And if A works for 3days and left, B will finish remaining work in 6days. In what days B alone will finish the work?
Solution :
3/a + 6/b =1---(i)
2/a + 9/b = 1---(ii)
work is equal
3/a + 6/b = 2/a + 9/b
b=3a
Sub in any equation(i)
==> 9/b + 6/b = 1
==> b = 1/15
B finish in 15 days
Ques 8.
If Pipe A is 5 times faster than Pipe B . and takes 32 minutes less to fill the tank than the pipe B . when will be the tank will be full if both pipes are open together ?
Solution :
5:1
Diff 4----32
1-----8
Total work 8*5=40
=40/(5+1) = 40/6
Ques 9.
A trader wants to sell a watch at 25% profit. If its cost price was Rs.x more, an extra profit of Rs.50 would be made on it. find x .
Solution :
25----100
50---- X
X =200
Ques 10.
A,B & C can do a work in 10, 12 & 15days respectively. They started work together. But A left the work before 5days of its completion. B also left the work 2days after A left. In how many days was the work completed.?
Solution :
(X-5)/10 + ( x-3)/12 + x/15 =1
==> X = 7days
