Answer:
86
Step-by-step explanation:
Given that there are 30 students in class 10R and the mean marks for the entire class was 70%. Therefore, total mark of class = 70 x 30 = 2100
Given that there are 20 boys in the class and the mean marks for the boys was 62 %. Therefore, total mark of boys = 62 x 20 = 1240
To calculate the mean mark for the girls we need to find the total number of girl and total mark of girls. total number of girl = 30 - 20 (boys) = 10 total mark of girls = total mark of class - total mark of boys = 2100 - 1240 = 860 mean mark for girls = 860 / 10 = 86
Answer:
12
Step-by-step explanation:
9×10⁴ is 300 times greater than 3×10²
as, (9×10⁴)/(3×10²)=3× 10²
and the proper of writting powers in computer form is a×10^b
Answer:
The symbol ⊥ means is perpendicular to
Step-by-step explanation:
(brainliest)
Answer:
18i, -7-i, -6+18i
Step-by-step explanation:
1. √-324
first take out the negative as √-1=i
√-324= i√324
324 =2*162
324=2*2*81
324=2*2*9*9
i√324=i√2*2*9*9= i* 2*9= 18i
3.
-4+7i-3-8i combine like terms
-4-3 -8i+7i = -7-i
5.
(1+5i)(4-2i) distribute
1*4 -1*2i +5i*4 -5i*(-2i) multiply
4 -2i +20i +10i² but i²= -1 so
4 -2i +20i -10 combine like terms
-6 +18i
