### Math Magic NCERT Book - Solutions

CBSE Class 5 Mathematics

NCERT Solutions
CHAPTER-1
THE FISH TALE

(1) At what price per kg did Fazila sell the king fish?

Sol (1) Price of 8kg king fish=Rs.1200

Price of 1kg king fish=Rs. (1200/8)

= Rs. 150

(2) Floramma has sold 10 kg prawns today. How much money did she get for that?

Sol. (2) Price of 1kg prawns= Rs. 150

Price of 10 kg prawns=Rs. (10 150)

=Rs. 1500

(3) Gracy sold 6 kg sword fish. Mini has earned as much money as Gracy. How many kg of sardines did Mini sell?

Sol. (3) Cost of 1 kg swordfish= Rs. 60

Gracy earned on selling 6 kg swordfish=Rs. (6 60) = Rs. 360

Earning of mini = Rs. 360

Cost of Sadines=Rs. 40 per kg

Quantity of sardines sold for Rs. 360= (360/40) kg= 9kg

(4) Basher has Rs.100. He spends one-fourth of the money on squid and another three-fourth on prawns.

(a) How many kilograms of squid did he buy?

(b) How many kilograms of prawns did he buy?

Sol. We have,

One-fourth of Rs.100 =Rs. (100/4) =Rs.25

Three-fourth of Rs.100= Rs. (100/4) 3 = Rs. (25 3) = Rs.75

(a) Cost of Squid= Rs. 50 per kg.

For Rs. 25, quantity of squid brought= half kg

[Half of Rs. 50 is Rs. 50]

(b) Cost of prawns= Rs. 150 per kg

For Rs. 75, quantity of prawns brought= half kg

[Half of Rs. 150 is Rs. 75]

Ques. Women's 'Meenkar Bank'

The meeting of the Meenkar Bank has just begun. Fazila is the president. Twenty fisherwomen have made their own bank. Each saves Rs. 25 every month and puts it in the bank.

1. How much money does the group collect each month?

2. How much money will be collected in ten years?

Sol. (1) Money collected by each member is Rs. 25 per month.

Money collected by the group of 20 members per month=Rs. (20 25) =Rs. 500

(2) Money collected by the group in 10 years= Rs. (10 12 500) =Rs. 60000

(a) Gracy took a loan of Rs. 4000 to buy a net. She paid back Rs. 345 every month for one year. How much money did she pay back to the bank?

Sol. (a) Loan taken by Gracy=Rs. 4000

Amount paid at the rate of Rs. 345 per month for one year= Rs. (345 12) =Rs. 4140

Gracy paid back to the bank Rs. 4140

(b) Jhansi and her sister took a loan of Rs. 21000 to buy a long boat. They paid back a total of Rs. 23520 in one year. How much did they pay back every month?

Sol. (b) Amount paid back by Jhansi and her sister to the bank in one year i.e. 12months =Rs. 23250

Amount paid back every month=Rs. (23250/12) =Rs. 1960

Ques. Why Don't We Start a New Fish-drying Factory?

The women of Meenkar Bank also want to start a factory to dry fish. The Panchayat has given them some land for that. Over the years they have saved Rs 74,000. They find out how much they will need for the factory. Fazila writes the things they need to buy to begin. See the table for the cost of each item and the number of items they want to buy. Find the total cost.

 Item Price of each No. of items Cost Borewell for fresh water Rs. 3000 1 Bamboo for fish drying Rs. 2000 20 Cement tank Rs. 1000 4 Tray and knife Rs. 300 20 Bucket Rs. 75 20

Total cost to set up the factory = ____________

When fresh fish is dried it becomes its weight. In one month they plan to dry 6000 kg of fresh fish. How much dried fish will they get in a month? ____________

Sol.

 Item Price of each No. of items Cost Borewell for fresh water Rs. 3000 1 Rs. (3000 1) =Rs. 3000 Bamboo for fish drying Rs. 2000 20 Rs. (2000 20) = Rs. 40000 Cement tank Rs. 1000 4 Rs. (1000 4) =Rs. 4000 Tray and knife Rs. 300 20 Rs. (300 20) = Rs. 6000 Bucket Rs. 75 20 Rs. (75 20) =Rs. 1500

Total cost to set up the factory = Rs. 54500

Quantity of dried fish obtained in one month= of 6000 kg = (6000/3) kg= 2000 kg

Ques. Let us first calculate for 6 kg of fresh fish.

We buy fresh fish for Rs. 15 per kg

We sell dried fish for Rs. 70 per kg

We dry 6 kg fresh fish to get ………. Kg dried fish

For 6 kg fresh fish we have to pay 6 ………. = Rs. 90

We will sell 2 kg dried fish and get 2 ………. = Rs.………

So if we dry 6 kg fresh fish we will earn ………-90= Rs. ……….

But it we dry 6000 kg we can earn Rs………… 1000 in one month!

Sol.  We dry 6 kg fresh fish to get 2kg dried fish [6/3=2]

For 6 kg fresh fish we have to pay 6 Rs. 15 =Rs. 90

We will sell 2kg dried fish and get 2 Rs. 70 =Rs. 140

So if we dry 6 kg fresh fish we will earn Rs. 140-Rs. 90= Rs. 50

But if we dry 6000 kg we can earn Rs 50 1000=Rs. 50000 in one month!

Ques. Jhansi- I found that for 6000 kg fish we would need 1500 kg salt every month! Its price is Rs. 2 per kg

Monthly costs:

(a) Salt 1500 2= Rs.………..

(b) Packing and bus charges= Rs. 3000

So the total monthly cost of drying and selling the fish =Rs. ………..

Fazila- That sounds very good! Our calculations tell us that every month our Bank will earn Rs. 44000!

1. Check to see if you also get the same answer.

Sol.  Monthly costs-

(a) Salt =1500 Rs. 2= Rs. 30000

(b) Packing and bus charges= Rs. 3000

So, the total monthly cost of drying and selling the fish=Rs. 3000+Rs. 3000= Rs. 6000

They earn Rs. (50000-6000) = Rs. 44000 per month

Their answer is correct.