From the condition, the incomes of A, B and C are 5x, 4x and 3x respectively, where x is the common measure for the three income values.
Similarly, their spendings are 8y, 5y and 4y, respectively, where y is the common measure for the three spending values.
We also are given that
5x - 8y = 80 (1) ("A save rupee 80") and
5x = 1200. (2) ("the income of A is 1200")
From eq(2), x = = 240; then from eq(1)
y = = = 140.
Now saving for B is 4x - 5y = 4*240 - 5*140 = 260. Answer
saving for B is 3x - 4y = 3*240 - 4*140 = 160. Answer
A has an income of 1200; and the ratio of incomes is A:B:C = 5:4:3. So B has an income of 960 (4/5 of 1200) and C has an income of 720 (3/5 of 1200).
A saves 80 of his income of 1200, so he spends 1120; and the ratio of spending is A:B:C = 8:5:4. So B spends 700 (5/8 of 1120) and C spends 560 (4/8 of 1120).
So B's saving is 960-700 = 260; C's saving is 720-560 = 160.