Question

Hi I need some help with these questions. Thanks :)

1. 3 consecutive odd numbers add to give 405. Find the smallest of the numbers.

2. 5 times a number less 7 is equal to 7 times the number plus 13. Find the number.

3. Chris earns four times Vesna's wage v and Vesna earns $17 more than Dawn. How many dollars does Chris earn if their combined wages are $163?

4. Percy is 8 years older than Ginny. In ten years time he will be three times Ginny's present age. How old is Percy now?

5. The two equal sides of an isosceles triangle are given as ( x + 2 ) cm and the third is ( x + 6 ) cm. I the perimeter of the triangle is 385 cm, find the value of x.

6. A choc frog is 11 cents dearer than a green frog. 3 green frogs and 2 choc frogs cost 57 cents. What is the cost of a choc frog I cents?

Answer 1

1. 3 consecutive odd numbers are x, x+2, x+4
     x+x+2+x+4=405
     x+x+x+2+4=405
     3x+6=405
     3x=399
     x=133 (smallest of the numbers)

2. Let the number =x
    5x-7=7x+13
    -7-13=7x-5x
    -20=2x
    x=-10

3. Chris earns 4v, Vesna earns v, Dawn earns v-17
    4v+v+v-17=163
    6v-17=163
    6v=180
    v=$30
   Chris earns 4v=$120
 
4. Ginny is x years old, Percy is x+8 years old
    In 10 years time, Percy will be x+8+10=3x
    x+18=3x
    18=2x
    x=9
    Percy is 9+8 years now=17 years

5. Perimeter of the triangle=sum of its sides
    385=x+2+x+2+x+6 
    385=3x+10
    375=3x
    x=125cm

6. A choc frog costs x. A green frog costs x-11
    2x+3(x-11)=57
    2x+3x-33=57
    5x=90
    x=18 cents
    A choc frog costs 18 cents