Power Play (Exponents) | FIO

Question 11

Identify the greater number in each of the following—

(i) 434^3 or 343^4

(ii) 282^8 or 828^2

(iii) 1002100^2 or 21002^{100}

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Solution

We will calculate the value of each given number and then compare them to find the greater one.

Step 1 — Comparing 434^3 and 343^4

First, let us find the value of 434^3. The exponent 3 tells us to multiply the base number 4 by itself three times.

43=4×4×44^3 = 4 \times 4 \times 4

=16×4= 16 \times 4

64\boxed{64}

Next, let us find the value of 343^4. The exponent 4 tells us to multiply the base number 3 by itself four times.

34=3×3×3×33^4 = 3 \times 3 \times 3 \times 3

=9×3×3= 9 \times 3 \times 3

=27×3= 27 \times 3

81\boxed{81}

Now, we compare the two calculated values. We see that 81 is greater than 64. So, 343^4 is the greater number.

Step 2 — Comparing 282^8 and 828^2

First, let us find the value of 282^8. The exponent 8 tells us to multiply the base number 2 by itself eight times.

28=2×2×2×2×2×2×2×22^8 = 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2

=4×2×2×2×2×2×2= 4 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2

=8×2×2×2×2×2= 8 \times 2 \times 2 \times 2 \times 2 \times 2

=16×2×2×2×2= 16 \times 2 \times 2 \times 2 \times 2

=32×2×2×2= 32 \times 2 \times 2 \times 2

=64×2×2= 64 \times 2 \times 2

=128×2= 128 \times 2

256\boxed{256}

Next, let us find the value of 828^2. The exponent 2 tells us to multiply the base number 8 by itself two times.

82=8×88^2 = 8 \times 8

64\boxed{64}

Now, we compare the two calculated values. We see that 256 is greater than 64. So, 282^8 is the greater number.

Step 3 — Comparing 1002100^2 and 21002^{100}

First, let us find the value of 1002100^2. The exponent 2 tells us to multiply the base number 100 by itself two times.

1002=100×100100^2 = 100 \times 100

10000\boxed{10000}

Next, let us consider the value of 21002^{100}. This number is extremely large. We can use the exponent rule (am)n=am×n(a^m)^n = a^{m \times n}. We can rewrite 21002^{100} as (210)10(2^{10})^{10}.

2100=(210)102^{100} = (2^{10})^{10}

First, let us calculate the value of 2102^{10}. This means multiplying 2 by itself ten times.

210=2×2×2×2×2×2×2×2×2×22^{10} = 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2

=1024= 1024

Now, we substitute this value back into the expression for 21002^{100}.

2100=(1024)102^{100} = (1024)^{10}

We need to compare 1000010000 with (1024)10(1024)^{10}. We know that 10241024 is much larger than 100100. Even 102411024^1 is already 10241024. If we calculate 102421024^2, it is 1024×1024=10485761024 \times 1024 = 1048576. This value, 10485761048576, is already much greater than 1000010000. Since 21002^{100} is (1024)10(1024)^{10}, it will be an incredibly large number. Therefore, 21002^{100} is the greater number.

Answer

(i) 343^4 is greater. (ii) 282^8 is greater. (iii) 21002^{100} is greater.

More questions in FIO

Q1

Express the following in exponential form:

(i) 6×6×6×66 \times 6 \times 6 \times 6

(ii) y×yy \times y

(iii) b×b×b×bb \times b \times b \times b

(iv) 5×5×7×7×75 \times 5 \times 7 \times 7 \times 7

(v) 2×2×a×a2 \times 2 \times a \times a

(vi) a×a×a×c×c×c×c×da \times a \times a \times c \times c \times c \times c \times d

Q2

Express each of the following as a product of powers of their prime factors in exponential form:

(i) 648

(ii) 405

(iii) 540

(iv) 3600

Q3

Write the numerical value of each of the following:

(i) 2×1032 \times 10^3

(ii) 72×237^2 \times 2^3

(iii) 3×443 \times 4^4

(iv) (3)2×(5)2(-3)^2 \times (-5)^2

(v) 32×1043^2 \times 10^4

(vi) (2)5×(10)6(-2)^5 \times (-10)^6

Q4

Find out the units digit in the value of 2224÷4322^{224} \div 4^{32}? [Hint: 4=224 = 2^2]

Q5

There are 5 bottles in a container. Every day, a new container is brought in. How many bottles would there be after 40 days?

Q6

Write the given number as the product of two or more powers in three different ways. The powers can be any integers.

(i) 64364^3 (ii) 1928192^8 (iii) 32532^{-5}

Q7

Examine each statement below and find out if it is 'Always True', 'Only Sometimes True', or 'Never True'. Explain your reasoning.

(i) Cube numbers are also square numbers.

(ii) Fourth powers are also square numbers.

(iii) The fifth power of a number is divisible by the cube of that number.

(iv) The product of two cube numbers is a cube number.

(v) q46q^{46} is both a 4th power and a 6th power (qq is a prime number).

Q8

Simplify and write these in the exponential form.

(i) 102×10510^{-2} \times 10^{-5}

(ii) 57÷545^7 \div 5^4

(iii) 97÷949^{-7} \div 9^4

(iv) (132)3(13^{-2})^{-3}

(v) m5n12(mn)9m^5n^{12}(mn)^9

Q9

If 122=14412^2 = 144 what is

(i) (1.2)2(1.2)^2

(ii) (0.12)2(0.12)^2

(iii) (0.012)2(0.012)^2

(iv) 1202120^2

Q10

Circle the numbers that are the same—

24×362^4 \times 3^6            64×326^4 \times 3^2            6106^{10}            182×6218^2 \times 6^2            6246^{24}

Q11

Identify the greater number in each of the following—

(i) 434^3 or 343^4

(ii) 282^8 or 828^2

(iii) 1002100^2 or 21002^{100}

Q12

A dairy plans to produce 8.5 billion packets of milk in a year. They want a unique ID (identifier) code for each packet. If they choose to use the digits 0–9, how many digits should the code consist of?

Q13

64 is a square number (828^2) and a cube number (434^3). Are there other numbers that are both squares and cubes? Is there a way to describe such numbers in general?

Q14

A digital locker has an alphanumeric (it can have both digits and letters) passcode of length 5. Some example codes are G89P0, 38098, BRJKW, and 003AZ. How many such codes are possible?

Q15

The worldwide population of sheep (2024) is about 10910^9, and that of goats is also about the same. What is the total population of sheep and goats?

(ii) 20920^9

(ii) 101110^{11}

(iii) 101010^{10}

(iv) 101810^{18}

(v) 2×1092 \times 10^9

(vi) 109+10910^9 + 10^9

Q16

Calculate and write the answer in scientific notation:

(i) If each person in the world had 30 pieces of clothing, find the total number of pieces of clothing.

(ii) There are about 100 million bee colonies in the world. Find the number of honeybees if each colony has about 50,000 bees.

(iii) The human body has about 38 trillion bacterial cells. Find the bacterial population residing in all humans in the world.

(iv) Total time spent eating in a lifetime in seconds.

Q17

What was the date 1 arab/1 billion seconds ago?

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