119 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
25 as many large potatoes as medium potatoes. There are
12 as many small potatoes as large potatoes. There are 4 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 |
119 kg |
Number of potatoes |
Large |
Medium |
Small |
2 |
5 |
|
2 |
|
1 |
2 p |
5 p |
1 p |
Total mass of potatoes
= 9 u + 7 u + 1 u
= 17 u
17 u = 119
1 u = 119 ÷ 17 = 7
Mass of large potatoes
= 9 u
= 9 x 7
= 63 kg
The number of large potatoes is repeated.
Total number of large potatoes
= 63 x 4
= 252
2 p = 252
1 p = 252 ÷ 2 = 126
Total number of small and medium potatoes
= 5 p + 1 p
= 6 p
= 6 x 126
= 756
Answer(s): 756