20
Step-by-step explanation:
Step 1:
Let the number be 50 and to find 40% of 50 is given interms of expression as follows
To express the percentage the following strategy is used
Eg: 40% = 
∴ To express 40% of 50 is
Step 2:
On simplification the above expression we could get
= 20
The surface area of a cylinder is define by the formula S.A.=2πrh+2<span>πr^2, where the first part of the formula refers to the lateral area, perimeter, or circumference and the second part to the area of the bases, which are circles.
On this exercise it is asked to find the lateral area of a cylinder whose radius is 6 cm, and has a height of 20cm. To find the lateral area of the cylinder you should substitute this values into the formula, S.A.=2</span>πrh, and as can be seen the answers are given in terms of <span>π or pi.
S.A.=2</span><span>πrh
S.A.=2</span><span>π(6cm)(20cm)
S.A.=2</span><span>π(120cm)
S.A.=240</span>π cm^2
The lateral area of the cylinder is 240<span>π cm^2 or in other words letter B from the given choices.</span>
