1. Ray writes a two digit number. He sees that the number exceeds 4 times the sum of its digits by 3. If the number is increased by 18, the result is the same as the number formed by reversing the digits. Find the number. a) 35 b) 42 c) 49 d) 57 Solution: Let the two digit number be xy. 4(x + y) +3 = 10x + y .......(1) 10x + y + 18 = 10 y + x ....(2) Solving 1st equation we get 2x - y = 1 .....(3) Solving 2nd equation we get y - x = 2 .....(4) Solving 3 and 4, we get x = 3 and y = 5 2. a, b, c are non negitive integers such that 28a+30b+31c = 365. a + b + c = ? a) Greater than 14 b) less than or equal to 11 c) 13 d) 12 In a calender, Number of months having 28 days = 1 Number of months having 30 days = 4 Number of months having 31 days = 7 28 x 1 + 30 x 4 + 31 x 7 = 365 Here, a = 1, b = 4, c = 7. a+b+c = 12 3. George can do a piece of work in 8 hours. Paul can do the same work in 10 hours, Hari can do the same wor...
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