Telanagana SCERT Solution Class VIII (8) Math Chapter 10 Direct and Inverse Proportions Exercise 10.1
(1) Cost of 5 meter cloths =210
Cost of 1 meter cloths = 210/5 =42
(i) Cost of 2 meter cloths = 42X2 =84
(ii) Cost of 4 meters cloths = 42X4 =168
(iii) Cost of 10 meter cloths = 42X10 =420
(iv) Cost of 13 meter cloths = 42X13 =546
(2)
No. Of apples | 1 | 4 | 7 | 12 | 20 |
Cost of apples | 8 | 4X8 =32 | 8X7 =56 | 8X12 =96 | 20X8 =160 |
(3) Cost of 48 bags paddy RS 16,800
Cost of 1 bags paddy 16,800/48 =350
Therefore, cost of 35 bags of paddy = 350X35 =12250.
(4) Monthly average expenditure of a family of 4 member is =2800
Monthly average expenditure of a family of 1 member = 2800/4 =700
Monthly average expenditure of a family of 3 member = 700X3 =2100
(5) Let, model length be x.
Ship Length = 28 m
Most height = 12 m
In ration 28/12 = x/9 (Then do cross multiply)
= x= 28X9/12 =21 cm.
(6) (i) Let length of the shadow be x
Then 5.6/10.5 = 3.2/x
x = 3.2 X 10.5/5.6
= 6m
(ii) Let the height of the pole be x
Then, 5.6/x = 3.2/5
= x= 5.6X5/3.2
= x= 8.75m
(7) 5 hour = 60X5 =30 minutes
In 25 minutes the truck travels 14 km
Then in 1 minutes the truck travels 14/25 km
In 300 minutes the truck travels 14/25 X 300 =168 km
(8) 16 2/3 = 50/3 kilogram = 50/3 X 1000 = 50,000/3
40 gram hold 12 sheets
Then 1 gram hold 12/40 sheets
Therefore, 50,000/3 gram hold 12/40 X 50,000/3 =5,000 sheets.
(9) (i) In 60 minutes the train travel = 75 km
Then in 20 minutes the train travels 75/60 X 20
=25 km
(ii) Again we know
Time = distance/speed
So, Time = 250/75
= 10/3 hours.
(10) Let the length of micro chip be x
Then, 40/1 = 18/x
= x= 1/40 X 18 =0.45 cm
(ii) Let the number of doctors and no. Of lawyers be y
Then, 35x+50y/x+y = 40
= 35x+50y= 40x+40y
= 10y = 5x
x/y = 10/5
x:y= 2:1