6. The breadth of a room 4rn high is one third of its length. If the cost of painting its walls at the rate of Rs. 5 per m' is Rs. 640. The
cost of carpeting its floor at the rate of Rs.
250 per m
(a) 13000
(c) 14000
(d) 15000​

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)

Step 1: 6x-10=1; step 2: 6x=11