Question
Rita walks from her home to office. If she walks at 8 km/h,
she arrives 20 minutes late. But if she walks at a speed of (5/2) m/s, she gets there just 5 minutes late. Find the distance between her home and office.Solution
ATQ,
Let distance = x km
Time at 8 km/h: T1 = x/8 hours
Speed = (5/2) m/s = (5/2) × (18/5) = 9 km/h
Time at 9 km/h: T2 = x/9 hours
Difference: T1 - T2 = 20 - 5 = 15 minutes = 15/60 = 1/4 hours
So, (x/8) - (x/9) = 1/4
LCM of 8 and 9 = 72
(9x - 8x)/72 = 1/4 → x/72 = 1/4 → x = 18
Four terms are in proportion. The first, second and fourth terms are 4, 22, and 33. Find the third term.
362Â Â Â 284Â Â Â 393Â Â Â Â 451Â Â Â Â 144Â Â Â Â Â 221
...(45)2 ÷ ∛729 + (35)2 ÷ 1.4 =?
The following expressions form a series followed by a (?). Find the odd one out first and then find that what will come in place of the question mark (?...
77 ? 190 257 331 412
...108   329   ?    2975    8928    26789  .Â
5, 11, 19, 29, 41, ?
101    222    78    247    ?    276
98    148    185    ?     228    238
Select the number from among the given options that can replace the question mark (?) in the following series.
8, 27, 64, 125, 216, ?
