Question
A boy goes to school with a speed of 70 km/h and comes
back with a speed of 55 km/h. find his average speed?Solution
Since the distance travelled by a boy (going to school and coming back from school) is equal. So, average speed = 2xy/(x + y) Average speed = (2 x 70 x 55)/(70 + 55) Average speed = (2 x 70 x 55)/125 = 61.6 km/hr
1140, ?, 1130, 1160, 1120, 1170
1, 7, 37, 187, 937, ?
10, 94, 115, 138, 163, ?
124, 180, 108, 198, ?, 220
What will come in place of the question mark (?) in the following series?
3.5, 9.5, 27.5, 81.5, 243.5, 729.5, ?
135, 148, ?, 184, 207, 236
230 192 172 ? 122 100
...11   6   7   12   26    ?    205.5
Find the missing number in the given number series.
1, 2, 3, 6, 11, 20, ?In each of the following series, one term is missing. Find the missing term.
2, 5, 11, 23, 47, ?