Which of the following is not true?

Three rational numbers lying between\(\frac{-5}{4}\) and \(\frac{1}{2}\)are

\(\frac{x+y}{2}\) is a rational number

Which of the following statements is always true?

The reciprocal of \({-3\over8 } \times {-24\over 13}\) is

What should be added to \(\frac { -3 }{ 4 } \) to get -1?

What should be subtracted from \(\frac { -3 }{ 4 } \) to get - 1?

Which of the following is the identity element?

Which of the following is the multiplicative identity for rational numbers?

Which of the following is neither positive nor a negative rational number?

Is the rational numbers closed under multiplication, Justify?

Using appropriate properties, find \({2\over5}\times({-3\over7})-{1\over6}\times{3\over2}+{1\over14}\times{2\over5}\)

Write the additive inverse of the following \(2\over8\) 

Write the additive inverse of the following  \(-5\over9\)

Write the additive inverse of the following  \(-6\over-5\)

Rahul got 150 marks out of 200 and Prabha got 180 marks out of 300. Whose performance is better?

Find the whole quantity if 5% of the quantity is 80.

18% of a class took part in a karate competition. If 18 students have taken part in it, then what is the total number of students in the class?

An item marked at Rs 840 is sold for Rs 714. What is the discount and discount %?

The list price of a frock is Rs 220. A discount of 20% is announced on it. What is the amount of discount on it and its sale price?

Find using distributivity. \( \{{7\over5}\times ({-3\over12}) \}+ \{{7\over16}\times {5\over12} \}\)

Find using distributivity. \(\{ {9\over16}\times {4\over12} \} +\{ {9\over 16}\times {-3\over 9} \}\)

Find the population of a city after 2 years, which is at present is 20 lakh, if the rate of increase is 5% p.a.

A sum of Rs 10,000 is borrowed at a rate of interest 15% p.a. for 2 years. Find the simple interest on this sum and the amount to be paid at the end of 2 years.

Factorise: 27x³ - 21x² + 15x⁴

Using and associativity of addition of rational numbers, express the following as a rational number.
\({5\over2}+{-3\over7}+{1\over2}+{4\over7}\)

The table shows the portion of some common materials that are recycled.

 (a) Is the rational number expressing the amount of paper recycled more than \({1\over2}\)or less than \({1\over2}\) ?
(b) Which items have a recycled amount less than \({1\over2}\) ?
(c) Is the quantity of aluminium cans recycled more (or less) than half of the quantity of aluminium cans?
(d) Arrange the rate of recycling the materials from the greatest to the smallest.
(e) What do you understand from recycling and how it is useful?

Complete the following crossword puzzle using the given direction.

Direction:
Across:
(1) The product of number by itself two times, is called its _______
(2) If three numbers a, band c are such that a² + b²= c² then they are called _____ Triplets.
(3) A number is a when it is a product of the same two numbers.
Down: (4) The numbers 2n, n²-1 and n² + 1 where n is a natural number show Pythagorean______.
(5) Finding is the inverse operation of squaring a number.
(6) A number which divides a _______ given number exactly is called a or divisor of that number.

In computing the area of a square. Shekhar used the formula for area of a square, while his friend Maroof used the formula for the perimeter of a square. Interestingly their answers were numerically same. Tell me the number of units of the side of the square they worked on.

Find the area of the following trapezium.

The edge of a cube is 2 cm. Find the total surface area of the cuboid formed by three such cubes joined edge to edge.

A road roller makes 250 complete revolution to move once over to level a road.
Find the area of the road levelled if the diameter of the road roller is 84 cm and length is 1 m.