book Maths Puzzle Numerical Ability

Mixing Antifreeze
A radiator holds 5 gallons of fluid. It is full with a 15% solution, how much fluid should be drained and replaced with 65% antifreeze mixture to result in a 40

Read Solution (Total 0)

book Other Question

Please solve with work: 3/8=x+1/4

the x+1 is over top of the 4. Like a fraction or maybe it means division. I really need help with this problem. With work because then that way I can use the formula for all the other ones. Thanks so much.... A train leaves a station and travels east at 72 km/h. Three hours later a second train leaves on a parrallel track and travels east at 120 km/h. When will it overtake the first train?