NCERT Solutions For Class 6 Maths Ratios and Proportions Exercise 12.3
Ex 12.3 Class 6 Maths Question 1.
If the cost of 7 m of cloth is ₹ 294, find the cost of 5 m of cloth.
Solution:
Using unitary method, we have cost of 7 m of cloth = ₹294
Cost of 1 m of cloth = ₹ 294/7
Cost of 5 m of cloth = ₹(294/7 x 5) = ₹(42 x 5)
= ₹ 210
Thus, the required cost = ₹ 210
Ex 12.3 Class 6 Maths Question 2.
Ekta earns ₹ 1500 in 10 days. How much she will earn in 30 days?
Solution:
In 10 days Ekta earn ₹ 1500
In 1 days Ekta will earn ₹ 1500/10
In 30 days Ekta will earn ₹ 1500/10 x 30 = ₹4500
Thus the money earned by Ekta in 30 days = ₹4500.
Ex 12.3 Class 6 Maths Question 3.
If it has rained 276 mm in the last 3 days, how many centimeters of rain will fall in one full week (7 days)? Assume that the rain continues to fall at the same rate.
Solution:
In last 3 days the rain falls = 276 mm .
In 1 day the rain falls = 276/3 mm.
in 7 days the rain will fall = 276/3 x 7 mm.
= 92 x 7 mm = 644 mm or 64.4 cm [∵ 1 cm = 10 mm]
Thus, the amount of rain fall in week = 64.4 cm.
Ex 12.3 Class 6 Maths Question 4.
Cost of 5 kg of wheat is ₹ 30.50.
(a) What will be the cost of 8 kg of wheat?
(b) What quantity of wheat can be purchased in ₹ 61?
Solution:
(a) Cost of 5 kg of wheat = ₹ 30.50
Cost of 1 kg of wheat = ₹ 30.50/5
Cost of 8 kg of wheat = ₹(30.50/5 x 8)
= ₹ 48.80
Thus, the required cost = ₹ 48.80
(b) The quantity of wheat purchased in ₹ 30.50 = 5 kg
The quantity of wheat purchased in ₹ 1 = 5/30.50 kg
The quantity of wheat purchased in ₹ 61 = 5 x 61/30.50 kg
Thus, the required quantity of wheat = 10 kg
Ex 12.3 Class 6 Maths Question 5.
The temperature dropped 15 degree Celsius in the last 30 days. If the rate of temperature drop remains the same, how many degrees will the temperature drop in the next ten days?
Solution:
In last 3,0 days the quantity of drop in temperature = 15 degree Celsius
In last 1 day the quantity of drop in temperature = 15/30 degree Celsius
In last 10 days the quantity of drop is temperature = 15/30 x 10 degree Celsius
= 5 degree Celsius
Thus the required drop in temperature in last 10 days = 5 degree Celsius.
Ex 12.3 Class 6 Maths Question 6.
Shaina pays ₹ 7500 as rent for 3 months. How much does she has to pay for a whole year, if the rent per month remains same?
Solution:
Amount of rent paid in 3 months = ₹ 7500
Amount of rent paid in 1 month = ₹ 7500/3
Amount of rent paid in 12 months = ₹ (7500/3 x 12)
= ₹ 30,000
Thus the required amount of rent paid in 1 year = ₹ 30,000.
Ex 12.3 Class 6 Maths Question 7.
Cost of 4 dozen bananas is ₹ 60. How many bananas can be purchased for ₹ 12.50?
Solution:
∵ 1 dozen = 12 units
∴ 4 dozen of bananas = 12 x 4 = 48 bananas
₹ 60 is the cost of 4 dozen = 4 x 12 = 48 bananas
₹ 1 is the cost of = 48/60 bananas 60.
₹ 12.50 is the cost of = 600/60bananas
= 10 bananas
Thus the required number of bananas = 10
Ex 12.3 Class 6 Maths Question 8.
The weight of 72 books is 9 kg. What is the weight of 40 such books?
Solution:
Weight of 72 books = 9 kg
Weight of 1 books = 9/72 kg
Weight of 40 books = 9/72 x 40 kg = 5 kg
Hence, the required weight = 5 kg.
Ex 12.3 Class 6 Maths Question 9.
A truck requires 108 litres of diesel for covering a distance of 594 km. How much diesel will be required by the truck to cover a distance of 1650 km?
Solution:
To cover 594 km, the amount of diesel required = 108 litres.
To cover 1 km, the amount of diesel will be , required =
108/594 litres
To cover 1650 km, the amount of diesel required = 108×1650/594 litres = 300 litres
Thus, the required amount of diesel = 300 litres.
Ex 12.3 Class 6 Maths Question 10.
Raju purchases 10 pens for ₹150 and Manish buys 7 pens for ₹ 84. Can you say who got the pens cheaper?
Solution:
For Raju,
Cost of 10 pen = ₹150
Cost of 1 pen = ₹ 150/10 = ₹ 15
For Manish,
Cost of 7 pens = ₹ 84
Cost of 1 pen = ₹ 84/7 = ₹12
∴ ₹ 12 < ₹ 15 Thus Manish got the pens cheaper than Raju.
Ex 12.3 Class 6 Maths Question 11.
Anish made 42 runs in 6 overs and Anup made 63 runs in 7 overs. Who made more runs per over?
Solution:
Number of runs made by Anish in 6 overs = 42
Number of runs made by him in 1 over = 42/6 = 7 runs.
Number of runs made by Anup in 7 overs = 63
Number of runs made by him in 1 over = 63/7 = 9 runs.
∴ 9 runs > 7 runs.
Thus, Anup has made more runs.