Secondary School (English Medium) (5 to 8) Class 8 - CBSE Question Bank Solutions

Find the value of x so that (–2)³ × (–2)^–6 = (–2)^{2x – 1}

Find the value of x so that (2^–1 + 4^–1 + 6^–1 + 8^–1)^x = 1

Find the value of x^–3 if x = (100)^{1 – 4} ÷ (100)⁰.

By what number should we multiply (–29)⁰ so that the product becomes (+29)⁰.

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

Find the multiplicative inverse of (–7)^–2 ÷ (90)^–1.

If `5^(3x - 1) ÷ 25 = 125`, find the value of x.

Find x so that `(2/9)^3 xx (2/9)^-6 = (2/9)^(2x - 1)`

By what number should `((-3)/2)^-3` be divided so that the quotient may be `(4/27)^-2`?

Find the value of n.

`6^n/6^-2 = 6^3`

Find the value of n.

`(2^n xx 2^6)/2^-3 = 2^18`

`(125 xx x^-3)/(5^-3 xx 25 xx x^-6)`

`(16 xx 10^2 xx 64)/(2^4 xx 4^2)`

If `(5^m xx 5^3 xx 5^-2)/5^-5 = 5^12`, find m.

A new born bear weighs 4 kg. How many kilograms might a five year old bear weigh if its weight increases by the power of 2 in 5 years?

The cells of a bacteria double in every 30 minutes. A scientist begins with a single cell. How many cells will be there after 12 hours?

The cells of a bacteria double in every 30 minutes. A scientist begins with a single cell. How many cells will be there after 24 hours?

Planet A is at a distance of 9.35 × 10⁶ km from Earth and planet B is 6.27 × 10⁷ km from Earth. Which planet is nearer to Earth?

An insect is on the 0 point of a number line, hopping towards 1. She covers half the distance from her current location to 1 with each hop. So, she will be at `1/2` after one hop, `3/4` after two hops, and so on.

1. Make a table showing the insect’s location for the first 10 hops.
2. Where will the insect be after n hops?
3. Will the insect ever get to 1? Explain.

An insect is on the 0 point of a number line, hopping towards 1. She covers half the distance from her current location to 1 with each hop. So, she will be at `1/2` after one hop, `3/4` after two hops, and so on.

Where will the insect be after n hops?