In a group 120 children there are teice as many boys as girls. how many girls are there?

40 girls 80 boys

Step-by-step explanation:

80/2=40

40+80=120

80 girls

Step-by-step explanation:

120/3 = 40.

40 x 2 = 80

question:

could we have options?

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92