21.

$$\begin{gathered} \mathrm{If} {\mathrm{a}}^2 = 1^3 + 2^3 + 3^3, {\mathrm{b}}^2 = 1^3 + 2^3 + 3^3 + 4^3 \\ \mathrm{and} {\mathrm{c}}^2 = 1^3 + 2^3 + 3^3 + 4^3 +\hspace{0.17em}{5}^3, \mathrm{then} \mathrm{the} \mathrm{value} \mathrm{of} \mathrm{a} + \mathrm{b} + \mathrm{c} \mathrm{is} \end{gathered}$$

• 33

• 31

• 27

• 25

Which of the following options does not demonstrate the achievement of skill objectives of teaching, school mathematics in upper primary stages?

• The pupil handles geometrical instruments with ease and proficiency

• The pupil measures accurately

• The pupil solves routine type of problems using a formula

• The pupil does written calculation with ease and speed

The mean of n observations is m,. If m² - m + 1 is added to each observation, what will be the value of new mean ?

• m² - 1

• m² - 2m + 1

• $\frac{{\mathrm{m}}^2 + 1}{\mathrm{n}}$

• 1 + m²

In reference to difference between teaching of Mathematics and teaching of Science, the wrong statement is

• Teaching of mathematics starts with well defined terms, axioms, theorems while teaching of science starts with evidence and explanations.

• Teaching of science involves only deductive process while teaching of mathematics involves a combination of both inductive and deductive processes

• Mathematics is a man-made universe while Science is a natural one

• In teaching of science, the results are validated through experiments, in teaching of mathematics experimentations are the means to verify some of the probable results

A learner exhibiting difficulty in sorting, recognising patterns, orienting numbers and shapes, telling time and measurement may have dyscalculia with difficulty in

• language processing

• visual-memory

• visual-motor coordination

• visual-spatial skills

A teacher gives the following problem related to 'discount' to the students for solving. "The Marked Prices (MP) of a shirt and sweater are <200 and ? 300 respectively and the discounts on the marked prices of shirt and sweater are 20% and 12%, respectively. While preparing the bill, the shopkeeper interchanged the discounts on these items by mistake. On getting the bill, Hamida noticed the mistake and paid the actual amount to the shopkeeper. How much money did Hamida pay to the shopkeeper?"

What value does the teacher try to promote through this problem?

• Co-operation

• Sympathy

• Compassion

• Honesty

$\left(14.96 \times {10}^{10}\right) - \left(3.84 \times {10}^8\right) \mathrm{is} \mathrm{expressed} \mathrm{in} \mathrm{standard} \mathrm{form} \mathrm{as}$

• 1492.16 x 10⁸

• 1.49216 x 10¹¹

• 14921.6 x 10⁹

• 14.9216 x 10¹⁰

In the product of(5x + 2) and (2x² - 3x + 5), the sum of the coefficients of x² and x is

• 9

• - 8 

• - 9

• 8

The graphs of lines x + 2y - 3 = 0 and 2x + 4y + 11 = 0

• intersect at each other

• coincide with each other

• are parallel to one another

• are perpendicular to each other

Which of the following is not a contributing factor responsible for Mathematics anxiety?

• Gender

• Nature of subject

• Examination system

• Curriculum