Secondary School (English Medium) (5 to 8) इयत्ता ८ - CBSE Question Bank Solutions for Mathematics

If possible, find a hook-up of prime base number machine that will do the same work as the given stretching machine. Do not use (× 1) machines.

If possible, find a hook-up of prime base number machine that will do the same work as the given stretching machine. Do not use (× 1) machines.

Find a repeater machine that will do the same work as a `(xx 1/8)` machine.

The left column of the chart lists the lengths of input chains of gold. Repeater machines are listed across the top. The other entries are the outputs you get when you send the input chain from that row through the repeater machine from that column. Copy and complete the chart.

Long back in ancient times, a farmer saved the life of a king’s daughter. The king decided to reward the farmer with whatever he wished. The farmer, who was a chess champion, made an unusal request:

“I would like you to place 1 rupee on the first square of my chessboard, 2 rupees on the second square, 4 on the third square, 8 on the fourth square, and so on, until you have covered all 64 squares. Each square should have twice as many rupees as the previous square.” The king thought this to be too less and asked the farmer to think of some better reward, but the farmer didn’t agree.

How much money has the farmer earned?

[Hint: The following table may help you. What is the first square on which the king will place at least Rs 10 lakh?]

The diameter of the Sun is 1.4 × 10⁹ m and the diameter of the Earth is 1.2756 × 10⁷ m. Compare their diameters by division.

Mass of Mars is 6.42 × 10²⁹ kg and mass of the Sun is 1.99 × 10³⁰ kg. What is the total mass?

By what number should (–15)^–1 be divided so that the quotient may be equal to (–5)^–1?

By what number should (–8)^–3 be multiplied so that the product may be equal to (–6)^–3?

Find x.

`(- 1/7)^-5 ÷ (- 1/7)^-7 = (-7)^x`

Find x.

`(2/5)^(2x + 6) xx (2/5)^3 = (2/5)^(x + 2)`

Find x.

2^x + 2^x + 2^x = 192

Find x.

`((-6)/7)^(x - 7) = 1`

Find x.

2^3x = 8^{2x + 1}

Find x.

5^x + 5^{x – 1} = 750

If a = – 1, b = 2, then find the value of the following:

a^b + b^a 

If a = – 1, b = 2, then find the value of the following:

a^b – b^a 

If a = – 1, b = 2, then find the value of the following:

a^b × b^a 

If a = – 1, b = 2, then find the value of the following:

a^b ÷ b^a 

Simplify:

`[(1/2)^2 - (1/4)^3]^-1 xx 2^-3`