Answer:
144 people were originally at the party.
Step-by-step explanation:
18 boys is one fifth of the second boys population, so the second population is 18x9 = 162. The original population would be 162-18, which equals 144.
P = 2(l + w)
p = 356
l = 96
356 = 2(96 + w)
356 = 192 + 2w
356 - 192 = 2w
164 = 2w
164/2 = w
82 = w
check....
p = 2(l + w)
356 = 2(96 + 82)
356 = 2(178)
356 = 356 (correct)
so the width (w) = 82 cm
1.7a + 0.3a = 0.8;
(1.7 + 0.3)a = 0.8;
2 x a = 0.8;
a = 0.8 ÷2;
a = 0.4;
