By Observation :
If we see, the pairs which are making 130
25,105
60,70
65,65
Total coins = 20
Given
-No. of coins q * 5 (q) + No. of coins r *5 (r) = 130 (where q<r)
we can rule out 65,65
25,105 can also be ruled out as 5*5(1) +21* 5(2) = 130 (but coins count >20)
Lastly check 60,70 pair and note
1) limitation is on value of q<r and
2)Numer of q coin + No. of r coin = 20
so if we want to meet this
14* 5(1) + 6*5(2) = 130
70 (Q) 60 (R)
If we see, the pairs which are making 130
25,105
60,70
65,65
Total coins = 20
Given
-No. of coins q * 5 (q) + No. of coins r *5 (r) = 130 (where q<r)
we can rule out 65,65
25,105 can also be ruled out as 5*5(1) +21* 5(2) = 130 (but coins count >20)
Lastly check 60,70 pair and note
1) limitation is on value of q<r and
2)Numer of q coin + No. of r coin = 20
so if we want to meet this
14* 5(1) + 6*5(2) = 130
70 (Q) 60 (R)