Solution :
0+6(1*6) = 6
6+18(3*6) = 24
24+36 (6*6)= 60
60+60 (10*6)= 120
120+90(15*6) = 210
6+18(3*6) = 24
24+36 (6*6)= 60
60+60 (10*6)= 120
120+90(15*6) = 210
Ques 2.
I. 4X^2+ 17X + 15 = 0 ; II. 12Y^2 + 19Y + 5 = 0
Solution :
(X+3)(4X+5) = 0
X = -3, -5/4
(4Y+5)(3Y+1) = 0
Y = -1/3,-5/4
X≤ Y
X = -3, -5/4
(4Y+5)(3Y+1) = 0
Y = -1/3,-5/4
X≤ Y
Ques 3.
Pavan can do a piece of work in 30 days. Rohan who is 50% more efficient than Pavan can finish the work in how many days.
Solution :
In one day work
done by pavan is 1/30 and rohan is 50% more efficient than pavan , so one day
work of rohan = (150/100)*1/30 = 1/20
So time taken by rohan will be 20 days
So time taken by rohan will be 20 days
Ques 4.
24 ×266 ÷ 19 – ? = 312 ÷ 12
Solution :
24 × 14 – ? = 26
336 – ? = 26
? = 336 – 26 = 310
336 – ? = 26
? = 336 – 26 = 310
Ques 5.
Ravi invested 10000 rupee in fixed deposit at the rate of 7% simple interest. After every 3 rd year he added interest to principal. Find the interest earned at the end of 6 years .
Solution :
For the first 3 years SI will be = 10000*7/100*3 = 2100
Now he add 3000 to the principal i.e = 10000+2100 = 12100
Now interest earned at end of 6th year = 12100*7/100*3 = 2541
Now he add 3000 to the principal i.e = 10000+2100 = 12100
Now interest earned at end of 6th year = 12100*7/100*3 = 2541
Ques 6.
The present age of Ravi is twice that of his brother. 10 years hence the ratio of their ages will be 21:13. What is the present age of his brother ?
Solution :
==>2x+10/x+10 = 21/13
==>26x+130 = 21x+210
==>5x=80
==>X = 16 years
==>26x+130 = 21x+210
==>5x=80
==>X = 16 years
Ques 7.
3 years ago, the average age of P, Q, and R was 30 years. Also 5 years ago, the average age of Q and R was 20 years. What is the present age of P?
Solution :
Sum of ages of P+Q+R 3
yrs ago = 30*3 = 90
So after 3 yrs, i.e. at present their total = 90 + 3*3 = 99
Similarly sum of present age of Q&R = 20*2+5*2 = 50
So present age of P = 99-50 = 49 years
So after 3 yrs, i.e. at present their total = 90 + 3*3 = 99
Similarly sum of present age of Q&R = 20*2+5*2 = 50
So present age of P = 99-50 = 49 years
Ques 8.
Find the effective annual rate of 12 percent per annum compounded half- yearly-
Solution :
Take principal as 100
and then calculate
Half - yearly Rate =
12/2 = 6
Time = 1*2 = 2 years
Amount = 100*(1+6/100)^ 2
Amount = 112.36
So effective rate is 12.36
Amount = 100*(1+6/100)^ 2
Amount = 112.36
So effective rate is 12.36
Ques 9.
The length and breadth of a rectangle are increased by 30% and 20% respectively. Its area will be increased by
Solution :
Inreased Area =
30+20+(30*20)/100
==> Area = 50+6 = 56
Ques 10.
A 60 litres milk-water mixture contains 60% milk. How much pure milk need to be added to this mixture to make the mixture 30% water?
Solution :
60 litres mixture contains 24 litres of water. When milk added to this, quantity of water will remain same
Let x litres of pure milk to be added, then
30% of (60+x) = 24
Solve, x = 20
Let x litres of pure milk to be added, then
30% of (60+x) = 24
Solve, x = 20