ML Aggarwal CBSE Solutions Class 7 Math 7th Chapter Ratio and Proportion Exercise 7.1
(1) Express the following ratios in simplest form:
(2) Find the ratio of each of the following in simplest form:
(i) Rs. 5 to 50 paise
(ii) 3 km to 300 m
(iii) 9 m to 27 cm
(iv) 15 kg to 210 g
(v) 25 minutes to 1.5 hours
(vi) 30 days to 36 hours.
SOLUTION Number 1 & 2:
(3) If A : B = 3:4 and B:C = 8:9, then find A:C.
(4) If A:B = 5:8 and B:C = 18:25, then find A:B:C.
(5) If 3A = 2B = 5C, then find A:B:C.
SOLUTION Number 3, 4, & 5:
(6) Out of daily income of Rs. 120, a labourer spends Rs. 90 on food and shelter and saves the rest. Find the ratio of his
(i) spending to income
(ii) saving to income
(iii) saving to spending.
(7) 5 grams of an alloy contains 15/4 grams copper and the rest is nickel. Find the ratio by weight of nickel to copper.
SOLUTION Number 6 & 7:
(8) A pole of height 3 metres is struck by a speeding car and breaks into two pieces such that the first piece is 1/2 of them second. Find the length of both pieces.
(9) Heights of Anshul and Dhruv are 1.04 m and 78 cm respectively. Divide 35 sweets between them in the ratio of their heights.
SOLUTION Number 8 & 9:
(10) Rs. 180 are to be divided among three children in the ratio 1/3 : 1/4 : 1/6. Find the share of each child.
(11) A natural number has been divided into two parts in the ratio 7:11. If the difference of two part is 20, find the number and two parts.
(12) A certain sum of money has been devided into two parts in the ratio 9:13. If the second part is Rs. 260, find the total amount.
(13) The ratio of the present ages of Anjali and Ashu is 2:3. Five years hence, the ratio of their ages will be 3:4. Find their present ages.
(14) The present ages of A and B are in the ratio 5:6. Three years ago, their ages were in the ratio 4:5. Find their present ages.
SOLUTION Number 12 , 13 & 14:
(15) Two numbers are in the ratio 5:6. When 2 is added to first and 3 is added to seconds, they are in the ratio 4:5. Find the numbers.
(16) The ratio of number of boys to the number of girls in a school of 1430 students is 7:6. If 26 new girls are admitted in the school, find how many new boys may be admitted so that the ratio of number of boys to the number of girls may be change to 8:7.
(17) Which ratio is greater
(i) 5:6 or 6:7
(ii) 13:14 or 17:32
SOLUTION Number 15, 16 & 17: