Geometrical Constructions — Maths STD 7 — Question

A die is thrown 100 times and outcomes are noted as given below:

Outcome:	1	2	3	4	5	6
Frequency:	21	9	14	23	18	15

If a die is thrown at random, find the probability of getting a/ an:

1. 3
2. 5
3. 4
4. Even number
5. Odd number
6. Number less than 3

Find the value of p, if the mean of the following distribution is 20

x:	15	17	19	20 + p	23
f:	2	3	4	5 p	6

In a public library, the librarian made the following observations in a particular week.

Days	Mon.	Tues.	Wed.	Thurs.	Fri.	Sat.
Newspaper readers	350	400	500	450	550	450
Magazine readers	200	450	300	250	100	50

1. Draw a double bar graph choosing an appropriate scale.
2. On which day, the number of readers in the library was maximum?
3. What is the mean number of magazine readers per day?

Find the missing frequency (p) for the following distribution whose mean is 7.68

x:	3	5	7	9	11	13
f:	6	8	15	p	8	4

Fill in the blanks in the table.

	Principal	Rate of interest (p.c.p.a.)	Time	Interest	Amount
i.	Rs 4200	7%	3 years
ii.		6%	4 years	Rs 1200
iii.	Rs 8000	5%		Rs 800
iv.		5%		Rs 6000	Rs 18000
v.		2.5%	5 years	Rs 2400

The following table shows the life expectancy (average age to which people live) in various countries in a particular year. Represent this data by a bar graph.

Country	Japan	India	Britain	Ethiopia	Cambodia
Life expectancy (in years)	76	57	70	43	36

Draw triangle with the measures given. In ∆PQR, l(PQ) = 4.5 cm, l(PR) = 11.7cm, m∠PQR = 90°.