12. A road race is 15 kilometers long. After the starting line, there are water stations every 0.3 kilometer. How many water stations are there?

50

Step-by-step explanation:

Given

there is 1 water station at every 0.3 KM

If there are n water stations at every 0.3 KM

then KM covered by them = n*0.3 = 0.3n

given that total KM covered is 15 km

Thus,

0.3n = 15

=> n = 15/0.3 = 50

Thus, there are 50 water stations.

3

step-by-step explanation:

in standard form:

a= dictionaries

b= maps

you have to buy 3 dictionaries, so put a 3 next to the a (dictionaries) so that you can multiply them by each other.

a3+b= 60 (the amount of money you have)

we already know the cost of a=15 so replace a with $15

($15 x 3)+b=60

multiply 15 and 3 to get $45 and replace it with $45

45+b=60

and then replace b with 15 to get the total:

45+15=60

that means you have $15 left after buying 3 dictionaries.

15 divided by the cost of a map ($5) equals 3.

so you can buy 3 maps.

sorry if it was confusing!