There are 24 boys and 16 girls in a hall, each holding coins in their hand. The mean number of coins for the children is 11, The mean number of coins for the boys is 9 Work out the mean number of coins for the girls.

14

Step-by-step explanation:

The computation of the mean number of coins for the girls is shown below:

Since there are 24 boys and 16 girls so the total children is 40

So the number of coins for all children is

= 40 × 11

= 440

And, the number of coins for all boys is

= 9 × 24

= 216

Now the mean is

= (440 - 216) ÷ 16 girls

= 14

y-1700=200(x+4)

step-by-step explanation:

200(x+4) is 200x + 800 she is saving 200 per week x is the weeks and the -1700 is. us that’s howmuch she already had

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places