Samacheer Kalvi Class 8 Maths Solutions Chapter 7 Information processing Exercise 7.4

Tamilnadu Samacheer Kalvi 8th Maths Solutions Chapter 7 Information processing Ex 7.4

 

Question 1. Find the best buy of the following purchases:
(i) A pack of 5 chocolate bars for Rs 175 or 3 chocolate bars for Rs 114?
(ii) Basker buy \( 1\frac { 1 }{ 2 } \) dozen of eggs for Rs 81 and Aruna buy 15 eggs for Rs 64.50?
Answer:
(i) To find the best buy, we calculate the cost per chocolate bar for each pack.

For the pack of 5 chocolate bars at Rs 175, each bar costs \( \text{Rs } \frac{175}{5} = \text{Rs } 35 \). For the pack of 3 chocolate bars at Rs 114, each bar costs \( \text{Rs } \frac{114}{3} = \text{Rs } 38 \). Since Rs 35 is less than Rs 38, buying the pack of 5 chocolate bars is the best option. It is always wise to compare unit prices to make sure you get the most value.
(ii) We need to compare the cost per egg for both Basker and Aruna. Basker bought \( 1\frac{1}{2} \) dozen eggs, which is \( 1.5 \times 12 = 18 \) eggs. He paid Rs 81 for 18 eggs, so each egg cost \( \text{Rs } \frac{81}{18} = \text{Rs } 4.50 \). Aruna bought 15 eggs for Rs 64.50, so each egg cost \( \text{Rs } \frac{64.50}{15} = \text{Rs } 4.30 \).Since Rs 4.30 is less than Rs 4.50, Aruna's purchase of 15 eggs for Rs 64.50 is the best buy.
In simple words: (i) To find the best deal, we check how much one chocolate bar costs in each pack. The pack of 5 bars makes each bar cheaper at Rs 35. (ii) We check the price per egg. Aruna bought eggs for Rs 4.30 each, which is cheaper than Basker's eggs at Rs 4.50 each.

🎯 Exam Tip: Always calculate the unit price (cost per single item) for all options when looking for the best buy. This helps make a clear comparison.

 

Question 2. Using the given picture find the total special offer price of fresh sweets and bakery products to buy \( \frac { 1 }{ 2 } \) kg laddu, 1 kg cake, 6 pockets of bread.
Answer: First, we calculate the special offer price for each item after a 20% discount.

For Laddu, the regular price for 1 kg is Rs 245. With a 20% discount, the saving is Rs 49, making the special price for 1 kg Rs 196. Since we need \( \frac{1}{2} \) kg of Laddu, its cost is \( \text{Rs } 196 \times \frac{1}{2} = \text{Rs } 98 \). For Chocolate Cake, the regular price for 1 kg is Rs 550. After a 20% discount, the saving is Rs 110, so the special price for 1 kg is Rs 440. For Bread, the regular price for 1 packet is Rs 20. With a 20% discount, the saving is Rs 4, making the special price for 1 packet Rs 16. For 6 packets, the total cost will be \( \text{Rs } 16 \times 6 = \text{Rs } 96 \). Adding these special prices together, the total cost for all items is \( \text{Rs } 98 + \text{Rs } 440 + \text{Rs } 96 = \text{Rs } 634 \). Discounts are a good way for stores to attract customers and for shoppers to save money.
In simple words: We calculated the discounted price for each item. Half a kilo of Laddu costs Rs 98, one kilo of cake costs Rs 440, and six packets of bread cost Rs 96. Adding these up, the total special offer price is Rs 634.

🎯 Exam Tip: When dealing with discounts and specific quantities, first calculate the discounted price per unit, then multiply by the exact quantity needed to find the final cost.

 

Question 3. Using the given picture prepare a price list. Suppose you plan to buy \( 1\frac {1}{2 } \) kg of apple, 2 kg of pomegranate, 2 kg of banana, 3 kg of mango, \( \frac { 1 }{ 2 } \) kg of papaya, 3 kg of onion, \( \frac { { 1 }{ 2 } \) kg of tomato, and 1 kg of carrot in shop 1, how much will you save compared to shop 2.
Answer: We compare the total cost of groceries between Shop 1 (which offers a flat 15% discount on all items) and Shop 2 (with regular prices). First, let's calculate the total cost for the shopping list in Shop 1 after the 15% discount:

The total cost for the items in Shop 1, after the 15% discount, is Rs 675.75. Next, let's calculate the total cost for the same items in Shop 2: The total cost for the items in Shop 2 is Rs 715. To find the saving, we subtract Shop 1's total from Shop 2's total: Saving \( = \text{Rs } 715 - \text{Rs } 675.75 = \text{Rs } 39.25 \). You will save Rs 39.25 by buying from Shop 1 compared to Shop 2. Always checking prices and offers helps in smart shopping.
In simple words: We calculated the total cost of groceries from two shops. Shop 1 had a 15% discount, making the total Rs 675.75. Shop 2 had no discount, with a total of Rs 715. Buying from Shop 1 would save you Rs 39.25.

🎯 Exam Tip: When comparing prices with discounts, always perform calculations for each item and then sum them up. Ensure you apply the discount to the correct base price before multiplying by the quantity.

 

Question 4. You want to buy some grocery items as per your shopping list that are given in the picture with their price. Also you have a bag that capacity of carrying 7 kg. Using weight ratio approach tabulate to find the total price and how much can you buy more grocery items within your budget of Rs 1000 and not exceeding 7 kg.
Shopping list
1. 2kg of red chili
2. 2 kg of coriander
3. 1 kg of garlic
4. 1 kg of tamarind
5. 2 kg of toor dal
Answer: We need to find the total cost of the shopping list and check if it fits within a budget of Rs 1000 and a bag capacity of 7 kg.

For 2 kg of red chilli at Rs 145/kg, the cost is \( \text{Rs } 2 \times 145 = \text{Rs } 290 \). For 2 kg of coriander at Rs 130/kg, the cost is \( \text{Rs } 2 \times 130 = \text{Rs } 260 \). For 1 kg of garlic at Rs 82/kg, the cost is \( \text{Rs } 1 \times 82 = \text{Rs } 82 \). For 1 kg of tamarind at Rs 99/kg, the cost is \( \text{Rs } 1 \times 99 = \text{Rs } 99 \). For 1 kg of toor dal at Rs 78/kg, the cost is \( \text{Rs } 1 \times 78 = \text{Rs } 78 \). Adding these costs, the total price for the shopping list is \( \text{Rs } 290 + 260 + 82 + 99 + 78 = \text{Rs } 809 \). The total weight of these items is \( 2 + 2 + 1 + 1 + 1 = 7 \) kg. Since the total cost (Rs 809) is less than the budget (Rs 1000) and the total weight (7 kg) matches the bag capacity, all items on the list can be bought. With Rs 191 remaining from the budget, one could potentially buy more small items, provided there is still space in the bag.
In simple words: The total cost for all items on the shopping list is Rs 809, and the total weight is 7 kg. This fits within the budget of Rs 1000 and the 7 kg bag limit. You would have Rs 191 left over.

🎯 Exam Tip: Always calculate both the total cost and the total weight of items to ensure they fit within your budget and carrying capacity limits.

 

Objective Type Questions

 

Question 5. Online or television advertisements influence people on spending decisions by
(a) using special music
(b) making them think that they need the item
(c) using attractive pictures
(d) All of the options
Answer: (d) All of the options
In simple words: Ads use music, pretty pictures, and smart words to make you feel like you need to buy what they are selling. They use all these things to influence your choices.

🎯 Exam Tip: Remember that advertisements are designed to persuade you, so always think critically about your real needs before making a purchase.

 

Question 6. When I go shopping, I will buy
(a) something that looks attractive
(b) something my friend has
(c) something that I need to purchase
(d) the first thing I see in the store
Answer: (c) something that I need to purchase
In simple words: When you shop, it's smart to buy only what you really need. This helps you save money and make good choices.

🎯 Exam Tip: Prioritizing your needs over wants helps you shop smartly and stay within your budget.

 

Question 7. The best shopping choice is to
(a) shop at brand name stores always buy
(b) compare the choices before buying
(c) the same thing my friends bought
(d) buy at a regular shop always
Answer: (b) compare the choices before buying
In simple words: The smartest way to shop is to look at different options and compare them. See what is best for you before you decide to buy something.

🎯 Exam Tip: Always compare products, prices, and quality from different sellers to ensure you get the best value for your money.