Aiman had a roll of wire. He made 35 stars and 20 triangles in a day. The length of wire he used for 5 triangles is the same as 4 stars. In the morning, he used 12.48 m of wire to make 4/7 of the stars and 7/10 of the triangles. He made the remaining stars and triangles in the afternoon.
(a) How many triangles can be made using the same length of wire used in the morning?
(b) What was the length of wire he used to make the remaining stars in the afternoon?
triangle wire length =tw = 4/5 sw the star wire length
s = number of stars in full day =35
t = number of triangles in full day =20
morning:
4/7 s = 4/7 * 35 = 20 stars
7/10 t = 2/10 * 20 = 7 triangles
wire length in morning = 12.48 = sw *20 + 4/5 sw *7 = 25.6 sw
so
sw = 12.48 / 25.6 = 0.4875 meters for a star
so
tw = 4/5 * sw = 0.390 meters for a triangle
I suspect you can take it from there.