If 40 is what percent of 200?

A pipe fills a tank in 6 hours another empties it in 8 hours. Both open: how long to fill?

A sum doubles itself in 8 years at simple interest. What is the rate?

In a class 60% passed math 70% passed English and 20% failed both. What % passed both?

What is the area of a circle with radius 7 cm using π = 22/7?

The sum of angles in a triangle is?

What is 15% of 200?

How many ways can 4 people be arranged in a line?

Using the BODMAS rule, solve: 18 ÷ 3 + 4 = ?

Using the BODMAS rule, solve: 12 − 4 × 2 = ?

Using the BODMAS rule, solve: 5² − [(6 + 2) ÷ 2] = ?