3 Marks Question

Question 13 Marks

A teacher placed textbooks that are 2.5 cm thick on a bookshelf. The teacher wanted to place 80 textbooks on the shelf. The bookshelf is 160 cm long. How many books could be placed on the shelf? Was there any space left? If yes, how much?

Answer

Given that, the teacher wanted to place 80 textbooks, each is 2.5 cm thick.
Total thickness required = 80 × 2.5 = 200 cm
The bookshelf is 160 cm long.
The thickness of one book is 2.5 cm.
Number of books that can fit $=\frac{160 cm}{2.5 cm}=64$
64 books could be placed on the shelf.
The total thickness of these books = 64 × 2.5 = 160 cm, which is the full length of the shelf.
The teacher wanted to place 80 textbooks, but only 64 textbooks can fit.
Therefore, there is no space left after placing the maximum number of books.

View full question & answer→

Question 23 Marks

Shyamala bought 3 kg of bananas at ₹ 30/- per kg. She counted 35 bananas in all. She sells each banana for ₹ 5/-. How much profit does she make selling all the bananas?

Answer

Given that Shyamala bought 3 kg of bananas at ₹ 30 per kg.
Total cost = 3 × 30 = ₹ 90
She sold 35 bananas for ₹ 5 each.
Total revenue = 35 × 5 = ₹ 175
Profit = Total revenue – Total cost
= 175 – 90
= ₹ 85

View full question & answer→

Question 33 Marks

A 210-gram packet of peanut chikki costs ₹ 70.5, while a 110-gram packet of potato chips costs ₹ 33.25. Which is cheaper?

Answer

Given cost of a peanut is ₹ 70.5 per 210 grams.
∴ Cost per gram $=\frac{70.5}{210}=0.3357$
and cost of potato chips is ₹ 33.25 for 110 grams.
∴ Cost per gram $=\frac{33.25}{110}=0.3023$
∵ 0.3023 < 0.3357.
Hence, potato chips are cheaper.

View full question & answer→

Question 43 Marks

3 litres of watermelon juice is shared among 8 friends equally. How much watermelon juice will each get? Express the quantity of juice in millilitres.

Answer

Here total quantity of juice = 3 litres
No. of friends = 8
∴ Juice per friend $=\frac{3}{8}$ litre
$=\frac{3}{8} \times 1000 ml$
$=\frac{3000}{8}$
= 375 ml

View full question & answer→

Question 53 Marks

If the perimeter of a regular polygon with 12 sides is 208.8 cm, what is the length of its side?

Answer

Here Perimeter = 208.8 cm
No. of sides = 12
Length 0f a side $=\frac{\text { Perimeter }}{\text { No. of sides }}$
$=\frac{208.8}{12}$
= 17.4 cm

View full question & answer→

Question 63 Marks

A 4 m long wooden block has to be cut into 5pieces of equal length. What is the length of each piece?

Answer

Here total length = 4 m
No. of pieces = 5
Length of each piece $=\frac{\text { Total length }}{\text { No. of pieces }}$
$=\frac{4}{5}$
= 0.8 m

View full question & answer→

Question 73 Marks

Multiplying the following numbers by 10, 100, and 1000 to complete the table.

	× 10	× 100	× 1000
5.7
23.02
0.92
0.306
24.67

Answer

	× 10	× 100	× 1000
5.7	57	570	5700
23.02	230.2	2302	23020
0.92	9.2	92	920
0.306	3.06	30.6	306
24.67	246.7	2467	24670

View full question & answer→

Question 83 Marks

In which of the following multiplications is the product less than 1? Can you find the answer without actually doing the multiplications?
(a) 7 × 0.6
(b) 0.7 × 0.6
(c) 0.7 × 6
(d) 0.07 × 0.06

Answer

Yes, we can find the answer without actual multiplication, only by using decimal place values.
Multiplying by a number greater than 1: The product is greater than the original number.
Multiplying by a number between 0 and 1: The product is less than the original number.
Multiplying two numbers between 0 and 1: The product will be less than both factors, and therefore definitely less than 1.
(a) Greater than 1.
(b) Less than 1.
(c) Greater than 1.
(d) Less than 1.

View full question & answer→

Question 93 Marks

The price of 1 kg of oranges is ₹ 56.50. What is the price of 2.250 kg of oranges? Can we write 56.50 as 56.5 and 2.250 as 2.25 and multiply? Will we get the same product? Why?

Answer

Price of 1 kg of oranges = ₹ 56.50
Price of 2.250 kg of oranges = 56.50 × 2.250
$\begin{array}{l}=\frac{5650 \times 2250}{100 \times 1000} \\ =\frac{12712500}{100000}\end{array}$
= ₹ 127.125
Now 56.5 × 2.25 = 127.125
Hence, we will get the same product.
The zeroes at the end of a decimal do not change its value.
As we saw, 56.50 is the same as 56.5, and 2.250 is the same as 2.25.
Hence, the product of the two numbers will be the same.

View full question & answer→

Question 103 Marks

The thickness of a rupee coin is 1.45 mm. What is the total height of the cylinder formed by placing 36 rupee coins one over the other? Write the answer in centimetres.

Answer

Thickness of 1 coin = 1.45 mm
Total thickness of 36 coins = 36 × 1.45
$\begin{array}{l}=\frac{36 \times 145}{100} \\ =\frac{5220}{100}\end{array}$
= 52.2 mm
Now 10 mm = 1 cm
$1 mm=\frac{1}{10} cm$
$\therefore 52.2 mm=\frac{52.2}{10}=5.22 cm$.

View full question & answer→

Question 113 Marks

Meenu bought 4 notebooks and 3 erasers. The cost of each book was ₹ 15.50, and each eraser was ₹ 2.75. How much did she spend in all?

Answer

Here cost of 1 notebook = ₹ 15.50
∴ Cost of 4 notebooks = 4 × 15.50
$=\frac{4 \times 1550}{100}$
$=\frac{6200}{100}$
= ₹ 62
and cost of 1 eraser = ₹ 2.75
∴ Cost of 3 erasers = 3 × ₹ 2.75
$=\frac{3 \times 275}{100}$
$=\frac{825}{100}$
= ₹ 8.25
∴ Total amount spent = 62 + 8.25 = ₹ 70.25

View full question & answer→

Question 123 Marks

Find the quotient by converting the denominator into 1, 10, 100, or 1000 and verify the solution by the long division method (division by place value):
$\frac{4827}{8}$

Answer

Given $\frac{4827}{8}$
To convert the denominator 8 into 1000, multiply both the Nr and Dr by 125.
$\frac{4827 \times 125}{8 \times 125}=\frac{603375}{1000}=603.375$
Verification
By following the steps:

We get 4827 ÷ 8 = 0603.375
Hence verified.

View full question & answer→

Question 133 Marks

Find the quotient by converting the denominator into 1, 10, 100, or 1000 and verify the solution by the long division method (division by place value):
$\frac{1217}{2}$

Answer

Given $\frac{1217}{2}$
To convert the denominator 2 into 10, multiply both the Nr and Dr by 5.
$\frac{1217 \times 5}{2 \times 5}=\frac{6085}{10}=608.5$
Verification
By following the steps:

∴ 1217 ÷ 2 = 608.5
Hence verified.

View full question & answer→

Question 143 Marks

Find the quotient by converting the denominator into 1, 10, 100, or 1000 and verify the solution by the long division method (division by place value):
$\frac{415}{4}$

Answer

Given $\frac{415}{4}$
To convert the denominator 4 into 100, multiply both the Nr and Dr by 25.
$\frac{415 \times 25}{4 \times 25}=\frac{10375}{100}=103.75$
Verification
By following the steps

∴ 414 ÷ 4 = 103.75
Hence verified.

View full question & answer→

MATHS 3 Marks Question

Test yourself on this topic