0 votes 0 votes In a $100$ meters race, $A$ beat $B$ by $10$ meter or $2$ second. What is the speed of $A$? $5$ Km/h $10$ Km/h $15$ Km/h $20$ Km/h Unknown Category ugcnetcse-oct2020-paper1 + – go_editor asked Nov 20, 2020 edited Nov 21, 2020 by soujanyareddy13 go_editor 1.1k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes We know both of them covers 100 m, but t(B) = t(A) +2 For last 10m, B took 2 sec more to cover that distance, hence Speed of B = 5 m/sec B covered 100 meters in 20 sec so, A covered 100 meters in 18 sec Speed of A = 100/18 * 18/5 = 20 Km/h Ashwani Kumar 2 answered Nov 21, 2020 Ashwani Kumar 2 comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes D. 20 Km/h .. Distance to cover = 100 m ... ## Formula used: Distance = Speed × Time .. Concept used: To convert m/s to km/h then multiply with 18/5 .. Calculation: A beats B by 10 meters or 2 seconds means B covers 10 meters distance in 2 seconds .. Speed of B = 10/2 = 5 m/s .. Total time is taken by B to complete 100 m race = 100/5 = 20 seconds .. A takes 2 seconds less to complete the race .. Time is taken by A to complete the race = 20 – 2 = 18 sec Speed of A = 100/18 m/s = (100/18) × (18/5) = 20 km/h .. The speed of A is 20 km/h .. wer 123 answered Nov 20, 2021 wer 123 comment Share Follow See all 0 reply Please log in or register to add a comment.