In which of the following tables x and y vary directly?
(i)
A | 7 | 9 | 13 | 21 | 25 |
B | 21 | 27 | 39 | 63 | 75 |
(ii)
A | 10 | 20 | 30 | 40 | 46 |
B | 5 | 10 | 15 | 20 | 23 |
(iii)
A | 2 | 3 | 4 | 5 | 6 |
B | 6 | 9 | 12 | 17 | 20 |
(iv)
A | 12 | 22 | 32 | 42 | 52 |
B | 13 | 23 | 33 | 43 | 33 |
(i) Directly proportional.
Eplanation: In this table value of ‘b’ is thrice the value of ‘a’ in all the columns. Therefore ‘a’ and ‘b’ are directly proportional.
(ii) Directly proportional.
Eplanation: In this table value of ‘b’ is half of the value of ‘a’ in all the the columns. Therefore ‘a’ and ‘b’ are directly proportional.
(iii) Not directly proportional.
Eplanation: In this table value of ‘b’ is not thrice the value of ‘a’ in all the columns. Therefore ‘a’ and ‘b’ are not directly proportional.
(iv) Not directly proportional.
Eplanation: In this table value of ‘b’ is not varying in the same ratio as the value of ‘a’ in all the columns. Therefore ‘a’ and ‘b’ are not directly proportional.