The speed of a bike increases by 7 km/hr after every 1

Solution

Since, the speed of the bike increases by 7 km/hr after every 1 hour, therefore the bike will travel 7 km extra after every 1 hour. Therefore, distance travelled by the bike in 1st hour = 10 km Distance travelled by the bike in 2nd hour = 10 + 7 = 17 km Distance travelled by the bike in 3rd hour = 17 + 7 = 24 km This form an AP i.e. 10, 17, 24………distance travelled in 14th hour Therefore, total distance travelled by the bike in 14 hours = sum of the AP Distance travelled in 14 hours = (n/2){2a + (n – 1)d} Where n = number of terms = 14, a = 1st term = 10 and d = common difference = 7 Therefore, distance travelled in 14 hours = (14/2){2 × 10 + (14 – 1) × 7} = (14/2)(20 + 91) = 777 km