Secondary School (English Medium) (5 to 8) कक्षा ८ - CBSE Question Bank Solutions

What will the following machine do to a 2 cm long piece of chalk?

In a shrinking machine, a piece of stick is compressed to reduce its length. If 9 cm long sandwich is put into the shrinking machine below, how many cm long will it be when it emerges?

Sanchay put a 1 cm stick of gum through a (1 × 3^–2) machine. How long was the stick when it came out?

Ajay had a 1 cm piece of gum. He put it through repeater machine given below and it came out `1/(100,000)` cm long. What is the missing value?

Shikha has an order from a golf course designer to put palm trees through a (× 2³) machine and then through a (× 3³) machine. She thinks she can do the job with a single repeater machine. What single repeater machine should she use?

Neha needs to stretch some sticks to 25² times their original lengths, but her (× 25) machine is broken. Find a hook-up of two repeater machines that will do the same work as a (× 25²) machine. To get started, think about the hookup you could use to replace the (× 25) machine.

Find two repeater machines that will do the same work as a (× 81) machine.

Find three machines that can be replaced with hook-ups of (× 5) machines.

The left column of the chart lists the lengths of input pieces of ribbon. Stretching machines are listed across the top. The other entries are the outputs for sending the input ribbon from that row through the machine from that column. Copy and complete the chart.

The distance between the Sun and the Earth is 1.496 × 10⁸ km and distance between the Earth and the Moon is 3.84 × 10⁸ m. During solar eclipse the Moon comes in between the Earth and the Sun. What is distance between the Moon and the Sun at that particular time?

A particular star is at a distance of about 8.1 × 10¹³ km from the Earth. Assuring that light travels at 3 × 10⁸ m per second, find how long does light takes from that star to reach the Earth.

A bought a tape recorder for Rs 8,000 and sold it to B. B in turn sold it to C, each earning a profit of 20%. Which of the following is true?

Latika bought a teapot for Rs 120 and a set of cups for Rs 400. She sold teapot at a profit of 5% and cups at a loss of 5%. The amount received by her is ______.

The original price of a washing machine which was bought for Rs 13,500 inclusive of 8% VAT is ______.

Avinash bought an electric iron for Rs 900 and sold it at a gain of 10%. He sold another electric iron at 5% loss which was bought Rs 1200. On the transaction he has a ______.

A TV set was bought for Rs 26,250 including 5% VAT. The original price of the TV set is ______.

40% of [100 – 20% of 300] is equal to ______.

______ expenses are the additional expenses incurred by a buyer for an item over and above its cost of purchase.

The marked price of an article when it is sold for Rs 880 after a discount of 12% is ______.

By selling an article for Rs 1,12,000 a girl gains 40%. The cost price of the article was ______.