Three sixth grade math problems 1. The circumference of an isosceles triangle is 48CM, and the waist length is 40% of the circumference. Find the length of the bottom 2. A workshop originally planned to produce 120 pieces of goods, but actually produced 20 pieces more than the original plan. What percentage of the original planned production is the actual production? What percentage of the overproduction? 3. The construction team originally planned to complete a section of highway in 14 days, but actually completed the task four days ahead of schedule. How many percent of the daily work efficiency has been improved compared with the original plan?

Three sixth grade math problems 1. The circumference of an isosceles triangle is 48CM, and the waist length is 40% of the circumference. Find the length of the bottom 2. A workshop originally planned to produce 120 pieces of goods, but actually produced 20 pieces more than the original plan. What percentage of the original planned production is the actual production? What percentage of the overproduction? 3. The construction team originally planned to complete a section of highway in 14 days, but actually completed the task four days ahead of schedule. How many percent of the daily work efficiency has been improved compared with the original plan?

1、48×（1-40%×2）=9.6 cm
A: the length of the bottom edge is 9.6 cm
2、20÷120×100%≈16.67%
20÷（120+20）×100%≈14.29%
A: the actual production is 16.67% of the planned production
14.29% over production
3、[1/（14-4）-1/14]÷（1/14）×100%=40%
A: the daily work efficiency is 40% higher than the original plan