Question
The average age of 13 girls is 40 years. If the age of
one more girl is added the average decreases by half a year. What is the age of new girl?Solution
Total age of 13 girls = 13 × 40 = 520 years If the age of one more girl is added the average decreases by half a year, ∴ Total age of 14 girls = 39.5 × 14 = 553 Now, Age of the new person = 553 – 520 = 33 years
What will come in place of the question mark (?) in the following series?
75, ?, 107, 148, 229, 390
What will come in place of the question mark (?) in the following series?
15, 90, 450, ?, 5400, 10800Â
31, 60, 118, 234, 466, ?
72, 216, 54, 270, ?, 315
18, 35, 68, 117, ?, 263Â
32, 48, 72, 108, 162, ?
In each of the following number series, one term is missing. Find the missing term.
5, 7, 12, 22, 39, 65, ?
64, 65, 73, 100, ?, 289
32   33    29   38    ?      47    11
...12, 24, 46, 78, 120, ?