(a) The electric field strength (E), due to a point charge is a measure of how much force an object would experience per unit of charge if it were placed in the field.
To calculate it, you need the charge of the point, the distance from the point charge, and a constant called Coulomb constant (k). The formula is E = k * q / r^2, where q is the charge, r is the distance and k is Coulomb constant. In this case, the charge is 2.4 Coulombs and the distance is 8.6 cm, when you calculate this you get E = 2.3*10^8 N/C.
So the electric field strength at a point 8.6 cm away from a point charge of 2.4 C is 2.3*10^8 N/C.
(b) The magnitude of the electric force on a charge of -3.4 microcoulombs that is 8.6 cm away from a point charge of 2.4 microcoulombs can be calculated using Coulombs law:
F = k * (q1*q2)/r^2
where k is Coulombs constant, q1 is 2.4 microcoulombs, q2 is -3.4 microcoulombs, and r is 8.6 cm.
The force magnitude is approximately equal to 1.97 * 10^-5 N.
Note that the direction of the force will be repulsive as the charges are opposite in sign.
(c) I won't draw a sketch for you, but to draw a sketch of two charges yourself:
You can draw a small circle for each charge, with the size of the circle representing the magnitude of the charge. Label the first charge with a + sign to indicate it's positive and the second charge with a - sign to indicate it's negative. Draw an arrow from the second charge towards the first charge to indicate the direction of the electric force, it should be pointing from the negative charge to the positive charge because the force is attractive.
I hope this helps some, I'm sorry I cannot answer completely.