Question 1:
Find the ratio of:
(a) Rs 5 to 50 paise (b) 15 kg to 210 g
(c) 9 m to 27 cm (d) 30 days to 36 hours
Answer:
(a) Rs 5 to 50 paise
1 rupee = 100 paise
5 rupee = 500 paise
Hence, the required ratio is 10:1.
(b) 15 kg to 210 g
1 kg = 1000 g
15 kg = 15000 g
Hence, the required ratio is 500:7.
(c) 9 m to 27 cm
1 m = 100 cm
9 m = 900 cm
Hence, the required ratio is 100:3.
(d) 30 days to 36 hours
1 days = 24 hrs
30 days = 24 × 30 = 720 hrs
Hence, the required ratio is 20:1.
Question 2:
In a computer lab, there are 3 computers for every 6 students. How many computers will be needed for 24 students?
Answer:
For 6 students, number of computers required = 3
∴ For 1 student, number of computers required =
∴ For 24 students, number of computers required = = 12 Hence, 12 computers are required for 24 students.
Question 3:
Population of Rajasthan = 570 lakhs and population of UP = 1660 lakhs.
Area of Rajasthan = 3 lakh km2 and area of UP = 2 lakh km2.
(i) How many people are there per km2 in both these States?
(ii) Which State is less populated?
Answer:
(i) Population of Rajasthan in 3 km2 area = 570 lakh
Population of Rajasthan in 1 km2 area =
Population of U.P in 2 km2 area = 1660 lakh
Population of U.P in 1 km2 area = = 830 lakh
(ii) It can be observed that population per km2 area is lesser for Rajasthan. Therefore, Rajasthan is less populated.