170 kg of potatoes are sorted into 3 sizes: large, medium and small. The ratio by mass of the large to medium to small potatoes is 9 : 7 : 1. There are
35 as many large potatoes as medium potatoes. There are
23 as many small potatoes as large potatoes. There are 3 large potatoes per kilogram. Find the total number of small and medium potatoes.
Mass of potatoes |
Large |
Medium |
Small |
Total |
9 u |
7 u |
1 u |
170 kg |
Number of potatoes |
Large |
Medium |
Small |
3 |
5 |
|
3 |
|
2 |
3 p |
5 p |
2 p |
Total mass of potatoes
= 9 u + 7 u + 1 u
= 17 u
17 u = 170
1 u = 170 ÷ 17 = 10
Mass of large potatoes
= 9 u
= 9 x 10
= 90 kg
The number of large potatoes is repeated.
Total number of large potatoes
= 90 x 3
= 270
3 p = 270
1 p = 270 ÷ 3 = 90
Total number of small and medium potatoes
= 5 p + 2 p
= 7 p
= 7 x 90
= 630
Answer(s): 630