New Learning Composite Mathematics Class 5 S.K. Gupta Anubhuti Gangal Commercial Arithmetic (Percentage, Profit and Loss) Chapter 15A Solution
Composite class 5 Commercial Arithmetic 15A
New Learning Composite Maths Class 5 S.K. Gupta Anubhuti Gangal Commercial Arithmetic (Percentage, Profit and Loss) Chapter 15A Solution by expert Math Teacher.
Learning Composite Maths Class 5 Commercial Arithmetic (Percentage, Profit and Loss) 15A
1) If 3 litres of petrol Cost ₹223.50, what is the cost of 10 litres of petrol?
Ans: If 3 litres of petrol cost ₹223.50
Then 1 litre of petrol cost ₹223.50/3 = ₹74.5
∴ The cost of 10 litre of petrol = ₹(74.5×10) = ₹745
2) If 7 erasers cost ₹21.84, find the cost of 11 erasers.
Ans: If 7 erasers cost ₹21.84
Then 1 eraser costs = ₹21.84/7 = ₹ 3.12
The cost of 11 erasers = ₹ (3.12×11) = 34.32
3) If one dozen bananas cost ₹60, what would be the cost of 8 bananas?
Ans: 1 dozen banana = 12 bananas
If the cost of 12 bananas = ₹60
Then the cost of 1 banana is = ₹ (60/12) = ₹5
The cost of 8 bananas = ₹ (8×5) = ₹ 40
4) If 26 ball pens cost ₹78, find the cost of 18 such pens?
Ans : If 26 ball pens cost ₹78
Then the cost of 1 ball pen is ₹ (78/26) = ₹ 3
The cost of 18 such ball pens is = ₹ (18×3)
5) A cook earns ₹4800 in 4 weeks. How much does he earns in 12 weeks?
Ans: If A cook earns in 4 weeks = ₹4800
Then the cook earns in 12 weeks = ₹ (4800×3) = ₹14400 [∵ 3× 4 weeks = 12 weeks]
6) If 5 gross clay boxes cost ₹21600, find the cost of 9 such clay boxes? [HINT: 1 gross = 12 dozen = 144]
Ans: 1 gross clay box = 12 dozen clay box= 144 clay box
∴ 5 gross clay box = 5×144 clay box = 720 clay box.
If the cost of 720 clay boxes is ₹21600
Then the cost of 1 clay box is ₹21600/72 = ₹300
So the cost of 9 clay boxes is = ₹300×9 = ₹2700
7) 8 scores of bananas cost ₹384. Find the cost of 85 bananas. [Hint: 1 score = 20]
Ans: 1 score of banana = 20 bananas
8 scores of banana = 160 bananas
Now if 160 bananas cost = ₹384
Then 1 banana costs = ₹384/160
The cost of 85 bananas = ₹ 384×85/160 = ₹204
8) If 2 dozen notebooks cost ₹960, find the cost of 1 score of notebooks.
Ans: 2 dozen notebooks = 24 notebooks
If 24 notebook cost ₹ 960
Then the cost of 1 notebook = ₹960/24 = ₹40
The cost of 20 notebooks = ₹40×20 = ₹800
The cost of 1 score of notebook = ₹800
9) Which is a better buy?
a) 3L milk for ₹105 or 5L milk for ₹180.
b) 2 kg onion for ₹ 130 or 5 kg onion for 310.
Ans:
a) In the first case the cost of 3 L milk Is ₹105 so the cost of 1 lit of milk is ₹ (105/3) = ₹35
in second case the cost of 5L milk is ₹180, so the cost of 1 link milk is ₹180/5 = ₹36
so the fist case where the cost of 3 lit milk is ₹105 is the better buy.
b) the first case where the cost of 2kg onion is ₹130. So the cost of 1kg onion is = ₹130/2 = ₹65
the second case where the cost of 5 kg onion is 310 . So the cost of 1 kg onion is = ₹(310/5) = ₹62
from the above results we can see that in the second case where the cost of 5 kg onion is the better option.
Composite class 5 Commercial Arithmetic 15A