a, b, c and d are in proportion.

Assertion (A): a - c, c, b - d, d are in proportion.

Reason (R): a, c, b and d are in proportion.

1. Assertion (A) is true, but Reason (R) is false.

2. Assertion (A) is false, but Reason (R) is true.

3. Both Assertion (A) and Reason (R) are correct, and Reason (R) is the correct reason for Assertion (A).

4. Both Assertion (A) and Reason (R) are correct, and Reason (R) is incorrect reason for Assertion (A).

Find the compounded ratio of

(a + b)² : (a - b)², (a² - b²) : (a² + b²) and (a⁴ - b⁴) : (a + b)⁴.

If a : b = 3 : 5, find (3a + 5b) : (7a - 2b).

The ratio of the shorter sides of a right-angled triangle is 5 : 12. If the perimeter of the triangle is 360 cm, find the length of the longest side.