ML Aggarwal CBSE Solutions Class 8 Math 6th Chapter Percentage and its Applications Exercise 6.1
(15) Let, total number of vote polled = x
∴ Loser polled = x X 42/100 = 42x/100
∴ Winner poled = x – 42x/100
= 100x – 42x/100 = 58x/100
∴ The difference between winner & loser polled = 58x/100 – 42x/100 = 16x/100
According to question –
16x/100 = 14400
Or x = 14400X100/16 = 90000
∴ Total numbers of vote polled = 90000 (Ans) (i)
Given, eligible voters = 100000
∴ Number of voter who do not give vote = (100000 – 90000)
= 10000 (Ans) (ii)
∴ Percentage of voter who do not give vote = 10000/100000 X100
= 10% (Ans) (iii)
(16) Total candidates = 8000
∴ Number of boys = 8000X 60/100
= 4800
∴ Number of girls = (8000 – 4800)
= 3200
Passed number of boys = 4800 X 80/100
= 3840
Passed number of girls = 3200 X 90/100
= 2880
Failed candidates = 8000 – (3840 + 2880)
= 8000 – 6720
= 1280 (Ans)
(17) Let, original price = x
According to question –
x + 16x/100 = 1479
Or, 100x + 16x/100 = 1479
Or, 116x/100 = 1479
Or, x = 1479X100/116 = 1275/- (Ans)
(18) Pratibha’s earlier weight = x
According to question –
x – 15x/100 = 59.5
Or, 100x – 15x/100 = 59.5
Or, 85x/100 = 59.5
Or, x = 59.5X100/85
Or, x = 70 kg (Ans)
(19) (i) Original price of article = 40/-
Price reduce = %
∴ Selling price = 40 – (40X 15/100)
= 40 – 6 = 34/- (Ans)
Let, original price = x
(ii) Selling price = 20.40/-
Price reduce = 15%
According to question –
x – 15x/100 = 20.40
Or, 100x – 15x/100 = 2040/100
Or, 85x = 2040
Or, x = 212040/85 = 24/- (Ans)
(20) Let max marks = x
Candidate ‘A’ gets = x X 36/100 = 36x/100
Candidate ‘B’ gets = x X 43/100 = 43x/100
According to question –
36x/100 + 24 = 43x/100 – 18
Or, 36x + 2400/100 = 43x – 1800/100
Or, 36x + 2400 = 43x – 1800
Or, 43x – 1800 = 36x + 2400 (No Sign change took place for fully interchange)
Or, 43x – 36x = 2400 + 1800
Or, 7x = 4200
Or, x = 4200/7
∴ max marks = 600 (Ans) (i)
Pass marks = (36X600/100) + 24
= 216+24 = 240
∴ Pass % = 240/600 X100 = 40% (Ans) (ii)
(21) Length of rectangle = L = 20cm
Breadth of rectangle = B = 15cm
Area of rectangle = A1 = (20X15) cm
= 300 cm2
Now, increase both side of length = {20+(20X20/100)}
= 24cm
Increase both side of breadth = {15+(15X20/100)}
= 18cm
∴ Area = A2 = (24X18)
= 432
∴ Increase area = A2 – A1 = 432 – 300
= 132 cm2
Increase area % = 132/300 X100 = 44%
(22) Let, Imran’s monthly income = x
Pocket money for two son = x X 1/100
= x/100
Elder son’s get amount = x/100 X 80/100
= 8x/1000
Elder son’s shear = 8x/1000 X 80/100
= 64x/10000
According to question –
8x/1000 – 64x/10000 = 60
Or, 80x – 64x/10000 = 60
Or, 16x = 60X10000
Or, x = 60X10000/16
Or, x = 37,500
∴ Month income of Imran = 37,500/-