Answer:
21 roads
Step-by-step explanation:
If each two cities are connected by a direct road, to find the number of roads we just need to solve a combination of 7 choose 2, that is, we need to find all pairs of two cities among the 7 cities:
Combination of 7 choose 2 = 7! / (5! * 2!) = 7*6/2 = 21
So there is a total of 21 roads on the island.
Answer:
1900
Step-by-step explanation:
1 kg = 1000g
1.2kg = x
<u>1</u><u> </u><u>kgx</u> = <u>1</u><u>2</u><u>0</u><u>0</u><u> </u><u>kg.g</u>
1kg. 1kg
x = 1200 g
1 decagram = 10g
40 decagram = x
<u>1</u><u> </u><u>dg.x</u> = <u>4</u><u>0</u><u>0</u><u> </u><u>dg.g</u>
1 dg. 1 dg
x = 400g
so the total= 1200g +300 + 400g=1900g
without the unit = 1900
