Question

pls help. 2 brigades have to build 115 km long road.
per day, first brigade builds 1.3 times longer road then second brigade.
how many kilometers of road has each brigade has to build, for them to start and finish work at the same time?​

Answer 1

Answer:

$The\ length\ of\ road\ to\ be\ built\ by\ the\ first\ brigade=65\ km\\The\ length\ of\ road\ to\ be\ built\ by\ the\ second\ brigade=50\ km$

Step-by-step explanation:

$We\ are\ given\ that,\\Length\ of\ the\ road\ the\ two\ brigades\ have\ to\ build\ together=115\ km\\Hence,\\Let\ the\ length\ of\ the\ road\ built\ by\ the\ second\ brigade\ be\ x\\Hence,\\The\ length\ of\ the\ road\ built\ by\ the\ first\ brigade=1.3x\\Hence,\\As\ we\ know\ that,\\Length\ of\ road\ built\ by\ the\ first\ brigade+ Length\ of\ the\ road\ built\ by\\ the\ second\ brigade=Total\ Length\ of\ the\ road\\Hence,\\x+1.3x=115\\2.3x=115\\x=\frac{115}{2.3}\\x=50\\Hence,$

$Let\ the\ length\ of\ the\ road\ built\ by\ the\ second\ brigade=x=50\ km \\Hence,\\The\ length\ of\ the\ road\ built\ by\ the\ first\ brigade=1.3x=1.3*50=13*5=65\ km$