Rational Numbers — MATHS STD 7 — Question

In a tennis competition, 128 players were selected for a series of knockout rounds. In each round the losers were eliminated and the winners reached the next round. How many players moved to the next round after 4th round? Express this number in the exponential notation in terms of the initial number of players.

Find the time in which Rs. 2,000 will amount to Rs. 2,330 at 11% p.a.?

Evaluate: 257.894 ÷ 0.169

Solve: 15 – 2 (5 - 3x) = 4 (x - 3) + 13

The lengths of the sides of two squares are in the ratio 8:15, find the ratio between their perimeters.

Simplify: 9x + 5 – [4x – {3x – 2 (4x – 3)}]

Five cards numbered 1 to 5 are placed in a bag. A card is drawn from the bag 30 times. Each time, the number on the drawn card is noted and the card drawn is replaced. The outcomes are tabulated as shown below :

Outcome	1	2	3	4	5
Frequency	4	10	7	5	4

If a card is now drawn at random, find the probability that the card drawn bears the number :
(i) 2
(ii) 3
(iii) 5