Answer:
C and B
Explanation:
31. Thrice means 3 times as much. Let's call Rahul and Shivam's present ages r and s respectively. We can write:
r = 3s
r + 8 = 1 + (s + 8) * 2
Simplifying the second equation gives us r + 8 = 2s + 17. When we substitute r = 3s into the second equation we get 3s + 8 = 2s + 17 which gives us s = 9. This means r = 9 * 3 = 27 so Rahul's age 8 years before the present is 27 - 8 = 19.
32. Let's call Ravi and Kishan's ages r and k. We can write:
r + k = 69
r - 8 = 2(k - 8) - 4
Rewriting the first equation gives us r = -k + 69 and when we substitute this into the second equation we get -k + 69 - 8 = 2k - 16 - 4. Solving for k we get k = 27 which means r = 42. 42 - 27 = 15.