Question:A batsman makes a scores of 87 runs in the 17th inning and thus increase his average by 3. Find his average after 17th inning.
Let the average after 17th inning = x. Then, average after 16th inning= (x-3). `:.` 16 (x -3) + 87 =17x. or x = (87 - 48) = 39 =
Question:Nine persons went to a hotel for taking their meals. Eight of them spent Rs. 12 each on their meals and the ninth spent Rs 8 more than the average expenditure of all the nine. What was the total money spent by them?
Let the expenditure be x. Then, average =`x/9` `:.` `8 xx 12 +(x/9 + 8)` = x or `x - (x/9)` = 104. or `(8x)/9` = 104 or x =`((104 xx 9)/8)` = 117
Question:There were 35 students in a hostel. Due to the admission of 7 new students, the expenses of the mess were increased by Rs 42 per day while the average expenditure per head diminished by Re 1. What was the original expenditure of the mess?
Let the total average expenditure be Rs. x then, 42 (x - 1) - 35x = 42 => 7x = 84 => x = 12 `:.` Origanl expenditure = Rs (35 x 12) = Rs 420
Question:If 30% of a certain number is 12.6, then find the number.
Let the required number be x. Then `30/100`x = 12.6 or x= `((12.6 xx 100)/30)` =42 `:.` Required number = 42
Question:The average of four consecutive even numbers is 27. Find the largest of these numbers.
Let the four consecutive even numbers be x, x + 2, x + 4, x + 6. Their total sum =(27 x 4) = 108 `:.` x + x + 2 + x + 4 + x + 4 + x + 6 = 108 or 4x = 96 or x = `96/4` or x = 24 `:.` Largest number = (x + 6) = (24 + 6) = 30