21.

Sum of first 20 terms of the Arithmetic Progression (AP) 11, 7, 3, ... is

• 20

• - 540

• 980

• - 65

$\mathrm{If} \mathrm{x} : \mathrm{y} = 3 : 4, \mathrm{then} \mathrm{find} \mathrm{the} \mathrm{value} \mathrm{of} \frac{2\mathrm{x} + 3\mathrm{y}}{3\mathrm{x} + 4\mathrm{y}}$

• $\frac{9}{25}$

• $\frac{18}{25}$

• $\frac{7}{18}$

• $\frac{17}{25}$

If a card is drawn from a pack of cards, what is the probability of getting a black coloured card?

• $\frac{1}{3}$

• $\frac{1}{2}$

• $\frac{3}{4}$

• $\frac{3}{8}$

To establish which type of correlation a mathematics teacher must have, versatile knowledge of basic elements of different subjects?

• Incidental correlation

• Systematic correlation

• Both (1) and (2)

• None of these

A bag contains 5 red balls, 8 white balls, 4 green balls and 7 black balls. If one ball is drawn at random find the probability that it is not green

• $\frac{1}{6}$

• $\frac{5}{6}$

• $\frac{5}{8}$

• $\frac{1}{2}$

0.46 x 0.46 + 0.54 x 0.54 + 0.92 x 0.54 = ?

• 1

• 10

• 11

• 0.12

What will come in place of question mark (?)

$\frac{17.28 ÷ ?}{3.6 \times 0.2} = 2$

• 120

• 1.2

• 12

• 0.12

If the price of an item A is 25% less than that of the item B. How much per cent is the price of B more than that of A ?

• 50

• $33\frac{1}{3}$

• $16\frac{2}{3}$

• 25

The expression x² - 2xy + y² - x + y has one
factor which is

• x - y = 1

• x + y = 1

• x - y - 1

• x + y + 1

Bhaskara's book 'Leelavati' was translated
into English by

• James taylor

• Mark taylor

• A.I. Babham

• None of these