Question
A car covers a distance of 60 km at a consistent speed.
If the car's speed is increased by 8 km/h, it would take 2 hours less to travel the same distance. What was the car's original speed?Solution
Let the actual speed of the car be 'x' km/h ATQ: Or, 60/x - 60/(x + 8) = 2 Or, 2x2 + 16x = 480 Or, x2 + 8x - 240 = 0 Or, x2 + 20x - 12x - 240 = 0 Or, x(x + 20) - 12(x + 20) = 0 Or, (x + 20)(x - 12) = 0 So, x = - 20, and x = 12 As speed cannot be negative So, x = 12 Original speed of the car is 12 km/hÂ
Find the wrong number in the given number series.
7, 14, 29, 58, 117, 233, 469
1, 1.5, 3, 7.5, 22.5, 75, 315
In each of the following, one term is wrong. Find the WRONG term.
7, 15, 29, 58, 117, 235
Find the wrong number in the given number series,
121, 130, 116, 139, 103, 148
- Find the wrong number in the given number series.
3, 6, 10, 15, 21, 29 121, 118, 122, 115, 127, 112
1024Â Â 3072Â Â Â 384Â Â Â 1152Â Â Â 145Â Â Â 432
Find the wrong number in the given number series.
15, 19, 36, 99, 355, 1379Â
2, 10, 30, 64, 130, 222
Find the wrong number in the given number series.
3, 7, 22, 89, 445, 2675