Simplify the following

1 1/2 - 1 ÷4/5+1/4​

At a lunchron, guests are offered a selection of five different grilled vegetables and four different meats. in how many waya could one choose three vegetables and two meats?

Two corresponding sides of two similar triangles are 3cm and 5cm. the area of the first triangle is 12cm^2. what is the area of the second triangle?

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.